LINEAR MOTION

You are responsible for worksheets & labs in addition to review questions

1. How can you be both at rest and also moving about 107,000 km/h at the same time?

2. You cover 10 meters in a time of 1 second. Is your speed the same if you cover 20 meters in 2 seconds? Explain.

3. Does the speedometer of a car read instantaneous speed or average speed? Why?

4. Which quantity, speed or velocity, does NOT depend of direction? Defend your answer.

5. What two controls on a car cause a change in speed? What control causes a non-speed change in velocity?

6. What is the acceleration of a car moving along a straight-line path that increases its speed from zero to 100 km/h in 10 s?

7. By how much does the speed of a vehicle moving in a straight line change each second when it is accelerating at 2 km/h/s? At 4 km/h/s? At 10 km/h/s?

8. What is the meaning of free fall ?

9. For a freely falling object dropped from rest, what is the instantaneous speed at the end of the fifth second of fall? The sixth second?

10. For a freely falling object dropped from rest, what is the acceleration at the end of the fifth second of fall? The sixth second? At the end of any elapsed time t ?

11. How far will a freely falling object fall from rest in five seconds? Six seconds?

12. How far will an object move in one second if its average speed is 5 m/s?

13. How far will a freely falling object have fallen from a position of rest when its instantaneous speed is 10 m/s?

14. Does air resistance increase or decrease the acceleration of a falling object?

15. Jake runs along a train flatcar that moves at the velocities shown at right. Calculate the relative velocities of Jake as seen by an observer on the ground for each situation. (To the right = +, to the left = -)

16. Below you see before and after snapshots of a car’s velocity. The time interval between before and after for each is the same.

a. Rank the cars in terms of the change in velocity (absolute value).

b. Rank them in terms of acceleration, from greatest to least (absolute value).

17. Calculate your average walking speed when you step 1 meter in 0.5 second.

18. Calculate the speed of a bowling ball that moves 8 meters in 4 seconds.

19. Calculate the distance (in km) you run if you maintain an average speed of 8 km/h for 1 hour.

20. These are drawings of same-size balls of different weights thrown straight downward. The speeds shown occur immediately after leaving the thrower’s hand. Ignore air resistance. Rank their accelerations from greatest to least.

21. Calculate the distance you will travel if you maintain an average speed of 10 m/s for 40s.

22. Calculate the acceleration of a car (in km/h/s) that can go from rest to 100 km/h in 10 s.

23. Calculate the acceleration of a bus that goes from 10 km/h to a speed of 50 km/h in 10s.

24. Calculate the acceleration of a ball that starts from rest and rolls down a ramp and gains a speed of 25 m/s in 5 seconds.

25. Calculate the instantaneous speed (in m/s) at the 10-second mark for a car that accelerates at 2 m/s2 from a position of rest.

26. Calculate the speed (in m/s) of a skateboarder who accelerates from rest for 3 seconds down a ramp at an acceleration of 5 m/s2.

27. Calculate the instantaneous speed of an apple 8 seconds after being dropped from rest.

28. A sky diver steps from a high-flying helicopter. If there were no air resistance, how fast would she be falling at the end of a 12-second jump?