MS Physics — every video script, narration first

Under each lesson: its atom, the script one beat per line (the on-screen column in grey), the attached question, the essential questions with keys shown, then the topic's mixed mastery quiz. Tap Fine or Change this under each; Copy all at the top pastes your rulings into the chat.

Topic 1 — Where something is, and whether it moved

Before we start: Motion

81 spoken words, about 40 s.

1Here is Jordan on a skateboard at the top of a ramp in a skate park.[a skate park; Jordan on a board at the top of a ramp; no title slide]
2He pushes off and rolls down the ramp.[he rolls down]
3He picks up speed, swerves around a cone, and rolls to a stop by the far wall.[faster; a swerve round an orange cone; he stops at the wall]
4How far did Jordan go, and how fast?[speech chips over the ramp: HOW FAR? HOW FAST?]
5To answer that, we will look at how to say where something is, how far it moved, and how fast it is going.[the ramp, the cone and the wall hold]
6Okay, so are you ready to get things moving?[the three replies appear]

A: Fine / B: Change this

T01 intro video

92 spoken words, about 46 s.

1Here is Maya on a bench in a park in Chicago, just back from a run.[a park bench by a path; Maya sitting, a watch on her wrist; no title slide]
2Her watch says she ran 2 400 meters.[the watch face: 2 400 m]
3But Maya is sitting on the very bench she started from.[a faint ghost of Maya at the same bench, labeled START]
4Her watch says 2 400 meters, yet Maya has ended up exactly where she began.[the watch face 2 400 m beside the START ghost]
5So how far did Maya really go?[question mark between the watch and the bench]
6To find out, we will look at how to say where something is, how to tell whether something moved, and how to measure how far it went.[the bench and the park path hold]
7Okay, so are you ready to get started?[the three replies appear]

A: Fine / B: Change this

T01 L01 — Every position is measured from a reference point

MOT-001 · Identify what a position is being measured from, and notice when that information is missing.

171 spoken words, about 86 s.

1Here is Maya in a park, waiting for a friend.[a map view of a park: a long trail, a parking lot at one end, a lake at the other; Maya's dot on the trail]
2She texts: I am 200 meters along the trail.[speech bubble: I am 200 meters along the trail.]
3Her friend texts back: 200 meters from where?[second bubble: 200 meters from where?]
4200 meters from the parking lot is one spot. 200 meters from the lake is another.[two faint dots light on the trail, one 200 m from the parking lot, one 200 m from the lake; chip 200 m by each]
5A reference point is an object that helps you say where something is.[chip REFERENCE POINT; the parking lot and the lake each get a pin]
6Where something is, compared to a reference point, is its position.[chip POSITION over Maya's dot]
7Now Maya sends a new text: I am 200 meters along the trail from the parking lot.[new bubble; the parking lot pin glows]
8The parking lot is the reference point. Now her position means one spot.[one dot stays, the other fades; chip REFERENCE POINT: PARKING LOT]
9Every position is measured from a reference point, even when nobody says so.[rule chip over the map]
10A highway sign says Mile 42. The miles are counted from the state line, so the state line is the reference point.[a green highway sign MILE 42; a long road drawn back to a line marked STATE LINE; pin on the state line]
11But a text that says the bus is 300 meters away has no reference point, because nobody has said away from what.[bubble: The bus is 300 meters away.; chip NO REFERENCE POINT]
12So, here's what we've seen: every position is measured from a reference point.[the park map with the parking lot pin; closing screen: one line — "Every position is measured from a reference point."]
13Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. A text message says: I am 150 m east along the beach. What is missing from this message?

  1. the number of meters it has gone
  2. the object it is measured from ✓
  3. the direction it is pointing in

Essential questions after the lesson (7)

1. A note on the counter says: The keys are 3 m to the left of the fridge. Which object is the reference point?

  1. the keys
  2. the fridge ✓
  3. the counter

2. A sign in a tunnel says: Exit, 400 m ahead. Which object is this position measured from?

  1. the sign ✓
  2. the exit
  3. the tunnel entrance

3. A message says: The dog is 20 m north of the big oak tree. Does this position have a reference point?

  1. yes ✓
  2. no

4. A message says: The picnic table is 50 m away. Does this position have a reference point?

  1. yes
  2. no ✓

5. An elevator button says: Floor 12. Which object is floor 12 counted from?

  1. the roof
  2. the ground floor ✓
  3. the elevator car

6. In the sentence 'The bike is 8 m to the right of the gate', what is the gate called?

  1. the reference point ✓
  2. the position
  3. the direction

7. What is the name for an object that helps you say where something is? (typed)

Accepted: reference point · a reference point · the reference point · reference points

A: Fine / B: Change this

T01 L02 — Moving or still, compared to a reference point

MOT-002 · Say whether something is moving or still, compared to a stated reference point.

173 spoken words, about 86 s.

1Here is a canoe tied up at a dock on a lake.[a lake from above; a dock with a pin labeled DOCK; the canoe beside it, roped on]
2Compared to the dock, is the canoe moving?[frame card: Compared to the dock, is the canoe moving?]
3No. Its position compared to the dock is staying the same.[cross beside the frame card; chip POSITION STAYING THE SAME]
4But now a paddler unties the canoe and paddles out across the lake.[the same canoe moves away from the dock, a wake behind it]
5Compared to the dock, is the canoe moving?[the frame card again]
6Yes. Its position compared to the dock is changing.[tick beside the frame card; chip POSITION CHANGING]
7And now the paddler stops, and the canoe drifts too slowly to see.[the same canoe, paddle up, barely creeping]
8Look away for a minute, then look back. The canoe sits farther from the dock than before.[screen dims for a beat; on return a faint ghost of the old spot and the canoe clearly farther out]
9Compared to the dock, is the canoe moving?[the frame card again]
10Yes. Its position compared to the dock changed, even though it moved slowly.[tick; chip POSITION CHANGING]
11But now the canoe drifts into the reeds and stops there.[the same canoe nosed into reeds at the shore]
12Compared to the dock, is the canoe moving?[the frame card again]
13No. Its position compared to the dock is staying the same.[cross; chip POSITION STAYING THE SAME]
14So, here's what we've seen: compared to a reference point, something is moving if its position is changing, and still if its position is staying the same.[the four canoe frames in a row with their ticks and crosses; closing screen: one line — "Moving means its position compared to the reference point is changing; still means it is staying the same."]
15Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. A bus pulls away from its stop. To decide whether the bus is moving compared to the stop, what do you check?

  1. whether its position compared to the stop is changing ✓
  2. whether its engine is running and making a noise
  3. whether any passengers are sitting inside the bus

Essential questions after the lesson (6)

1. A kite's string breaks, and the kite drifts across the field, away from the post it was tied to. Compared to the post, is the kite moving?

  1. yes ✓
  2. no

2. A bicycle is locked to a bike rack outside a store all morning. Compared to the rack, is the bicycle moving?

  1. yes
  2. no ✓

3. A model train runs around a circular track, passing the same station again and again. Compared to the station, is the train moving?

  1. yes ✓
  2. no

4. A snail crawls along a garden wall so slowly that you cannot see it move. An hour later it is near the gate instead of near the shed. Compared to the shed, is the snail moving?

  1. yes ✓
  2. no

5. A dog lies asleep on a porch all afternoon. Compared to the porch steps, is the dog moving?

  1. yes
  2. no ✓

6. Elena marks the edge of a tree's shadow with a stick. For a whole minute the edge stays at the stick, so Elena says the shadow is not moving. An hour later, the edge lies a step away from the stick. Is Elena correct?

  1. yes
  2. no ✓

A: Fine / B: Change this

T01 L03 — Moving compared to one thing, still compared to another

MOT-003 · Show how the same object can be moving compared to one thing and still compared to another.

167 spoken words, about 84 s.

1Here is Jordan sitting on a train that is pulling out of the station.[side view: a train car with Jordan in a window seat; the platform behind, a tree beside the track; the train begins to roll right]
2Is Jordan moving? That depends on the reference point.[question mark over Jordan]
3Compared to the platform, is Jordan moving?[pin on the platform: REFERENCE POINT: PLATFORM; frame card: Compared to the platform, is Jordan moving?]
4Yes. His position compared to the platform is changing.[tick; the gap between Jordan and the platform grows]
5And compared to a tree beside the track, is Jordan moving?[pin moves to the tree: REFERENCE POINT: TREE; frame card]
6Yes. His position compared to the tree is changing too.[tick; the gap between Jordan and the tree grows]
7But now compare Jordan to the seat next to him.[pin on the empty seat beside Jordan: REFERENCE POINT: SEAT; the view rides along with the train]
8Compared to the seat, is Jordan moving?[frame card]
9No. His position compared to the seat is staying the same.[cross; the gap between Jordan and the seat stays fixed]
10And compared to his backpack on the rack above him, is Jordan moving?[pin on the backpack: REFERENCE POINT: BACKPACK; frame card]
11No. His position compared to the backpack is staying the same.[cross; the gap stays fixed]
12The same Jordan, at the same moment, is moving compared to the platform and still compared to the seat.[split screen: left the platform view with a tick MOVING, right the in-train view with a cross STILL]
13So, here's what we've seen: the same object can be moving compared to one reference point and still compared to another.[the split screen holds]
14Whether something is moving depends on the reference point you choose.[closing screen: one line — "Whether something is moving depends on the reference point you choose."]
15Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. On a moving train, a passenger is still compared to her window but moving compared to a barn outside. Why does the answer change?

  1. The passenger changed her speed.
  2. The reference point changed. ✓
  3. The train slowed down.

Essential questions after the lesson (6)

1. Marcus sits still in his seat on a moving bus. Compared to a mailbox on the sidewalk, is Marcus moving?

  1. yes ✓
  2. no

2. A pilot sits in the cockpit of a plane flying over Kansas. Compared to a farmhouse on the ground, is the pilot moving?

  1. yes ✓
  2. no

3. Marcus sits still in his seat on a moving bus. Compared to the seat in front of him, is Marcus moving?

  1. yes
  2. no ✓

4. A pilot sits in the cockpit of a plane flying over Kansas. Compared to the plane's control panel, is the pilot moving?

  1. yes
  2. no ✓

5. A cup sits on a table inside a moving camper van. Compared to which reference point is the cup moving?

  1. the table
  2. the camper van's floor
  3. a cow in a field ✓

6. A girl stands still on a moving escalator in a mall. Compared to which reference point is the girl still?

  1. the step she stands on ✓
  2. a shop sign on the wall
  3. a boy walking down the stairs beside her

A: Fine / B: Change this

T01 L04 — The distance something travels is the whole length of its path

MOT-004 · Work out the total distance something travels along its path.

163 spoken words, about 82 s.

1Here is Maya walking her dog from her front gate to the dog park.[a map view: three streets at right angles; Maya's dot at the gate; the park gate at the far end; a N arrow top right]
2She walks 90 meters along Maple Street to the corner.[a dashed grey part grows from the gate to the corner; label 90 m beside its middle]
3She turns and walks 40 meters along Oak Street to the crosswalk.[second dashed part; label 40 m]
4Then she turns again and walks 60 meters along Pine Street to the park gate.[third dashed part; label 60 m; END dot at the park gate]
5The line Maya walked along is called her path.[the three dashed parts glow together; chip PATH]
6How far did Maya walk? To find out, add up the length of every part of her path.[chip: ADD UP EVERY PART]
7First, write down the length of each part.[working panel, line 1: 90 m / 40 m / 60 m stacked]
8Then add them up.[working panel, line 2: 90 m + 40 m + 60 m = 190 m]
9Maya walked 190 meters.[chip 190 m over the whole path]
10Her path turned two corners, but every part of it counts.[the two corners pulse]
11And now the dog runs off along a curved line through the grass, chasing a ball.[inside the park: a dashed curve from the gate to a ball]
12The dog's path is one curve, and that curve measures 48 meters.[label 48 m beside the curve]
13So the dog runs 48 meters.[chip 48 m]
14So, here's what we've seen: the distance something travels is the total length of its path, every part added up.[the street map with its three labeled parts and the 190 m chip; closing screen: one line — "The distance something travels is the total length of its path, every part added up."]
15Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. A robot vacuum moves 4 m forward, then turns and moves 2 m to the left. How far does it travel in total?

  1. 2 m
  2. 4 m
  3. 6 m ✓

Essential questions after the lesson (6)

1. A delivery robot drives 120 m east along a hallway, then 80 m north along another hallway. How far does the robot travel? Type the number of meters. (typed number)

Accepted: 200 · 200 m · 200 meters · 200 metres

2. A cart is pushed 45 m north, then 70 m east, then 25 m south across a park. How far does the cart travel in total? Type the number of meters. (typed number)

Accepted: 140 · 140 m · 140 meters · 140 metres

3. A swimmer swims 25 m to the far end of a lane, then 15 m back toward where she started. How far does the swimmer travel? Type the number of meters. (typed number)

Accepted: 40 · 40 m · 40 meters · 40 metres

4. A go-kart drives along a curved track from the start line to the finish line. Two lengths are marked on the drawing. Which length is the distance the kart travels?

  1. 28 m
  2. 36 m ✓

5. A walker goes 60 m east, 30 m south, 60 m west and 30 m north around a city block, back to the corner she started from. How far does she travel? Type the number of meters. (typed number)

Accepted: 180 · 180 m · 180 meters · 180 metres

6. A trail map lists a hike in three parts: 300 m to a creek, 450 m to a lookout, then 250 m to the summit. How far is the whole hike? Type the number of meters. (typed number)

Accepted: 1 000 · 1 000 m · 1 000 meters · 1 000m

A: Fine / B: Change this

T01 L05 — How far it ended from the start

MOT-005a · Work out how far something ended up from where it started.

164 spoken words, about 82 s.

1Here is Maya at the steps of a straight beach boardwalk.[a number line along a boardwalk, ticks every 10 m, the steps at 0 marked START]
2She walks 80 meters east to the ice-cream stand.[a dashed part grows right from 0 to 80; label 80 m east]
3Then she turns around and walks 30 meters west to a bench.[a second dashed part, below the first, from 80 back to 50; label 30 m west; END dot at 50]
4The distance she traveled is the total length of her path.[working panel: Distance traveled: 80 m + 30 m = 110 m]
5Maya traveled 110 meters.[chip 110 m over the two parts]
6But how far is she from the start?[question mark between START and END]
7The start is the reference point, so measure from the steps.[pin on the steps: REFERENCE POINT: START]
8Draw the straight line from the steps to the bench.[a solid dark-blue line from 0 to 50 along the number line; working panel: From the start: 80 m − 30 m = 50 m]
9The bench is 50 meters from the steps.[chip 50 m on the blue line]
10Her path measures 110 meters.[the dashed parts glow; chip 110 m]
11But her straight line measures 50 meters.[the blue line glows; chip 50 m]
12Now consider a different walk. Maya hikes 400 meters along a winding trail to a dock.[a map: a dashed winding trail from a parking lot START to a dock END; label 400 m along the path]
13On the map, the straight line from her start to the dock measures 150 meters.[a solid dark-blue line from START to END; label 150 m]
14So Maya ended 150 meters from the start.[chip 150 m on the blue line]
15So, here's what we've seen: how far something ended from the start is the length of the straight line from the start to the end.[the boardwalk with its blue line; closing screen: one line — "How far something ended from the start is the length of the straight line from the start to the end."]
16Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. A dog runs 10 m straight away from a gate, then 4 m back toward it. How far from the gate does the dog end?

  1. 4 m
  2. 6 m ✓
  3. 14 m

Essential questions after the lesson (6)

1. A remote-control car drives 60 m east along a straight park path, then 20 m back west. How far from where it started does the car end? Type the number of meters. (typed number)

Accepted: 40 · 40 m · 40 meters · 40 metres

2. A crab walks 9 m west along a straight line in the sand, then 4 m east. How far from where it started does the crab end? Type the number of meters. (typed number)

Accepted: 5 · 5 m · 5 meters · 5 metres

3. A boat sails along a curved path from a pier to a lighthouse. Two lengths are marked on the drawing. Which length is how far the boat ended from the pier?

  1. 600 m ✓
  2. 900 m

4. A bee flies 7 m east from its hive along a straight line, then 11 m west. How far from the hive does the bee end? Type the number of meters. (typed number)

Accepted: 4 · 4 m · 4 meters · 4 metres

5. A runner runs once around a 400 m track and stops exactly on the line she started from. How far from where she started does the runner end? Type the number of meters. (typed number)

Accepted: 0 · 0 m · 0 meters · 0 metres

6. An ant wanders from a crumb to its nest. Two lines are drawn between the ant's start and its end. Which line shows how far the ant ended from its start?

  1. the straight line from the start to the end ✓
  2. the line that wanders from the start to the end

A: Fine / B: Change this

T01 L06 — Which way it ended from the start: displacement

MOT-005b · Say which direction something ended up from where it started.

174 spoken words, about 87 s.

1Here is Maya at the steps of a beach boardwalk.[the boardwalk number line, the steps at 0 marked START]
2She walks 80 meters east to the ice-cream stand.[dashed part from 0 to 80; label 80 m east]
3Then she walks 30 meters west to a bench.[second dashed part from 80 back to 50; label 30 m west; END dot at 50]
4The bench is 50 meters from the steps.[working panel: From the start: 80 m − 30 m = 50 m; a solid dark-blue line from 0 to 50]
5But which way did she end up? The bench is east of the steps.[an arrowhead appears on the blue line at 50, pointing east; chip EAST]
6So Maya ended 50 meters east of the steps.[chip 50 m east on the blue arrow]
7How far something ended from the start, and which way, is called its displacement.[chip DISPLACEMENT over the blue arrow]
8Maya's displacement is 50 meters east.[the blue arrow labeled 50 m east, chip DISPLACEMENT]
9Now consider a different day.[the same boardwalk, cleared; START at 0]
10Maya walks 20 meters east from the steps.[dashed part from 0 to 20; label 20 m east]
11Then she walks 70 meters west, past the steps.[second dashed part from 20 to −50; label 70 m west; END dot at −50]
12The distance she traveled is 90 meters.[working panel: Distance traveled: 20 m + 70 m = 90 m]
13But Maya ended 50 meters west of the steps.[working panel: From the start: 70 m − 20 m = 50 m; a solid dark-blue arrow from 0 to −50 pointing west; chip WEST]
14So her displacement is 50 meters west.[the blue arrow labeled 50 m west]
15Both days she ended 50 meters from the start.[both boardwalks stacked: 50 m east above, 50 m west below]
16But the direction was different, so the displacement was different.[the two arrows pulse, one east, one west]
17So, here's what we've seen: displacement is how far something ended from the start, and which way.[the stacked boardwalks hold]
18Distance along the path is not the same as displacement.[day 2: the dashed path labeled 90 m beside the blue arrow labeled 50 m west; closing screen: one line — "Displacement is how far something ended from the start, and which way."]
19Okay, now your turn.[the attached question appears]

Attached question (after “Okay, now your turn.”)

1. A hiker walks 600 m east from a cabin, then 200 m back west. What is the hiker's displacement from the cabin?

  1. 400 m east ✓
  2. 400 m west
  3. 800 m east

Essential questions after the lesson (8)

1. A kayak is paddled 300 m east along a straight river, then 100 m west. What is the kayak's displacement?

  1. 200 m east ✓
  2. 200 m west
  3. 400 m east
  4. 400 m west

2. A delivery cart is pushed 60 m west along a straight hallway, then 25 m east. What is the cart's displacement?

  1. 35 m east
  2. 35 m west ✓
  3. 85 m east
  4. 85 m west

3. A cat walks 12 m east along a straight fence, then 12 m west, back to where it started. What is the cat's displacement?

  1. 0 m ✓
  2. 12 m east
  3. 12 m west
  4. 24 m east

4. A snowplow drives 500 m north along a straight road, then 200 m farther north. What is the snowplow's displacement?

  1. 300 m north
  2. 300 m south
  3. 700 m north ✓
  4. 700 m south

5. A route card says: the bus ended 3 000 m from where it started. Does this describe the bus's displacement?

  1. yes
  2. no ✓

6. A route card says: the bus ended 2 500 m south of where it started. Does this describe the bus's displacement?

  1. yes ✓
  2. no

7. A drone lands 300 m north of the spot it took off from. What is '300 m north of the take-off spot' called?

  1. the drone's distance
  2. the drone's displacement ✓
  3. the drone's path

8. What is the name for how far something ended from where it started, and which way? (typed)

Accepted: displacement · a displacement · the displacement · displacements

A: Fine / B: Change this

T01 mixed mastery quiz (15 items)

1. A parked car sits in a driveway all night. Compared to the garage door, is the car moving?

  1. yes
  2. no ✓

2. A hiker walks 200 m east, then 150 m north, then 200 m west around a pond. How far does the hiker travel? Type the number of meters. (typed number)

Accepted: 550 · 550 m · 550 meters · 550 metres

3. A tugboat moves 500 m north along a straight canal, then 200 m south. What is the tugboat's displacement?

  1. 300 m north ✓
  2. 300 m south
  3. 700 m north
  4. 700 m south

4. A woman stands still on a moving walkway at an airport. Compared to the walkway's moving belt, is she moving?

  1. yes
  2. no ✓

5. A swimmer swims 50 m east along a straight pool, then 50 m west, then 50 m east again. How far from where she started does the swimmer end? Type the number of meters. (typed number)

Accepted: 50 · 50 m · 50 meters · 50 metres

6. A passenger sits still on a moving subway train. Compared to which reference point is the passenger still?

  1. the station platform
  2. the seat she sits in ✓
  3. a lamp post outside

7. A dog runs 15 m from its owner to a tree, 15 m back to its owner, then 15 m to the tree again. How far does the dog run in total? Type the number of meters. (typed number)

Accepted: 45 · 45 m · 45 meters · 45 metres

8. The minute hand of a wall clock looks still whenever you glance at it. Ten minutes later it points at a different number. Compared to the numbers on the clock face, is the minute hand moving?

  1. yes ✓
  2. no

9. A delivery van drives along a winding road from a depot to a farm. The road is 8 km long, and the straight line from the depot to the farm is 5 km long. How far from the depot does the van end?

  1. 3 km
  2. 5 km ✓
  3. 8 km
  4. 13 km

10. A train travels 800 m west along a straight track, then 300 m east. What is the train's displacement?

  1. 500 m east
  2. 500 m west ✓
  3. 1 100 m east
  4. 1 100 m west

11. A bird flies 90 m south from its nest, then 90 m north, back to the nest. What is the bird's displacement?

  1. 0 m ✓
  2. 90 m north
  3. 90 m south
  4. 180 m south

12. A note says: The cat is 2 m to the left of the couch. Which word names what the note tells you about the cat?

  1. its position ✓
  2. its distance
  3. its path

13. A map pin shows where the library is. What is the word for where something is? (typed)

Accepted: position · a position · the position · its position

14. In the sentence 'The tent is 40 m uphill from the big rock', the big rock is the object the tent's position is measured from. What is such an object called? (typed)

Accepted: reference point · a reference point · the reference point · reference points

15. A sign at the end of a trail says: You are now 2 000 m north of the trailhead. Which word names what the sign gives: how far from the start, and which way? (typed)

Accepted: displacement · a displacement · the displacement · displacements

A: Fine / B: Change this

T01 summary video

185 spoken words, about 92 s.

1Here is everything we found out about where something is, and whether it moved.[PART 1 — the park map with a pin; title chip]
2A reference point is an object that helps you say where something is.[chip REFERENCE POINT on the pin]
3Where something is, compared to a reference point, is its position.[chip POSITION]
4Every position is measured from a reference point.[rule chip]
5Compared to a reference point, something is moving if its position is changing, and still if its position is staying the same.[two stills: the canoe away from the dock with a tick MOVING; the canoe at the dock with a cross STILL]
6The same object can be moving compared to one reference point and still compared to another.[the split-screen still: the train from the platform; the seat from inside]
7So whether something is moving depends on the reference point you choose.[chip: IT DEPENDS ON THE REFERENCE POINT]
8Okay, now your turn.[question 1 appears — END OF PART 1]
9Here is everything we found out about how far something went.[PART 2 — the boardwalk number line as a still]
10The line a moving object travels along is called its path.[chip PATH on the dashed parts]
11The distance something travels is the total length of its path, every part added up.[chip DISTANCE on the dashed parts]
12How far something ended from the start is the length of the straight line from the start to the end.[the dark-blue straight line from START to END]
13How far something ended from the start, and which way, is called its displacement.[arrowhead on the blue line; chip DISPLACEMENT]
14Distance along the path is not the same as displacement.[the dashed path and the blue arrow side by side; closing screen: two bullets — • Distance is how far along the path. • Displacement is how far from the start, and which way.]
15Okay, now your turn.[questions 2 and 3 appear — END OF PART 2]

Attached questions

1. A coach says: The ball is 4 m from the goal post. Which object is the reference point in that sentence?

  1. the ball
  2. the goal post ✓
  3. the coach

2. A jogger runs 300 m north along a straight road, then 100 m south. What is the jogger's displacement?

  1. 200 m north ✓
  2. 200 m south
  3. 400 m north

3. A skateboarder rides 50 m east along a straight path, then 50 m west, back to where she started. How far does she travel along her path?

  1. 0 m
  2. 50 m
  3. 100 m ✓

A: Fine / B: Change this