Displacement and velocity, with a frame of reference
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
East is positive. At t = 0, Ari's cart A is at x = 0 moving 4 m/s; cart B is at x = 60 m moving -2 m/s. When do they meet?
East is positive. At t = 0, Esme's cart A is at x = 0 moving 8 m/s; cart B is at x = 75 m moving 3 m/s. When do they meet?
A ship sails 40 km at 30° north of east, then 30 km due north. What is its displacement from the start, Kira?
- 70 km, adding the two lengths
- About 61 km, 55° north of east
- About 61 km, 35° north of east
- 50 km north, ignoring the eastward part
A plane has an airspeed of 250 m/s. The wind blows 50 m/s toward the east. To fly due north, what heading and ground speed does Luz need?
- Head 11.5° west of north; ground speed 250 m/s
- Head due north; ground speed about 245 m/s, drifting east
- Head 78.5° west of north; ground speed about 245 m/s
- Head 11.5° west of north; ground speed about 245 m/s
Milo says: "I drove 120 km in 2.0 h, so my average velocity was 60 km/h." The trip ended 30 km from the start. Find the flaw.
- The average velocity is 30 km/h, the distance from the start
- 60 km/h is the average speed; the average velocity is 15 km/h
- The average velocity is 60 km/h, but the speed is 15 km/h
- No flaw: speed and velocity mean the same thing here
Noah says two cars at 60 km/h have equal velocities. One drives east, the other north. Judge the claim and find their relative velocity.
- False: only the speeds match; relative velocity is about 85 km/h
- False: only the speeds match; relative velocity is 120 km/h
- True: both are 60 km/h, so the relative velocity is 0
- False: only the speeds match; relative velocity is 60 km/h
Read this first
Position each second (example data)
time (s) position (m) 1 1 2 4 3 9 4 16 5 25 Pia says the velocity at 3 s is 8 m/s, the slope from 3 s to 5 s in the position table. Judge the claim.
- Not supported: the velocity at 3 s is about 7 m/s, from 3 s to 4 s
- Supported: the slope from 3 s to 5 s is the velocity at 3 s
- Not supported: the velocity at 3 s is 9 m/s, its position
- Not supported: the velocity at 3 s is about 6 m/s; 8 m/s is later
Rain falls straight down at 6.0 m/s. Ren cycles east at 8.0 m/s. What is the rain's speed relative to the cyclist, and its angle from the vertical?
- 10 m/s, 53° from the vertical, coming from ahead
- 10 m/s, 53° from the vertical, coming from behind
- 10 m/s, 37° from the vertical, coming from ahead
- 14 m/s, 53° from the vertical, coming from ahead
Tala rides a moving escalator up in 20 s, or walks up the stopped escalator in 30 s. How long to walk up the moving one?
- 25 s, the average of 20 and 30
- 50 s, the sum of 20 and 30
- 10 s, the difference of 20 and 30
- 12 s: the two rates add up
Zee rides a train at a steady 20 m/s. A friend stands on the platform. Both watch the same falling ball. Which quantity do they measure the same?
- Its velocity, since the ball is one object in both views
- Its displacement in 1 s, since the clock time is shared
- Nothing: each frame sees a different motion of the ball
- Its acceleration: the frames differ by a steady velocity
