Chapter 3 Review Acceleration and Free Fall

1. When an object undergoes a change in velocity, it is said to be ______________.ans: accelerating/decelerating

2. What is the equation that will define the final velocity with a change in displacement at a constant acceleration?

ans: Vf2 = Vi2 + 2a∆d3. What is the acceleration due to gravity

when a ball is thrown into the air?ans – 9.8 m/s2

4. What would a graph showing constant acceleration look like?

ans: 2velocity (m) 1

Time (s)

5. In the graph above, which has the slower rate of acceleration?

ans: #1, can you explain why?

6. What is the acceleration due to gravity when a ball is dropped from a defined height?

ans: 9.8 m/s2

7. What is the equation used to find the final velocity of an object at a constant acceleration in time?

Ans: Vf = Vi + a∆t

8. What does the following graph indicate?

velocity (m)

ans: zero acceleration Time (s)

9. The equation used to find the distance an object travels at a constant acceleration in time is:

ans: ∆d = Vi∆t + ½ a∆t2

10.What is the ONLY difference between acceleration along the horizontal and free fall?

ans: substitute g for a and g is always the same11. What is the average acceleration of an object

that travels at 5.0 m/s for 3.2 min?ans: 0.026 m/s2

12. An object fall starting from rest for 5.4 s. How far will the object travel in this time?

ans: 143 m13. What would be the velocity of the object in

#12 in the time interval stated?ans: 53 m/s

14. You throw a ball into the air with an initial velocity of 2.3 m/s. What is the velocity of the ball at the very top of the throw?

ans: zero, gravity has brought the ball to 0 m/s before reversing.

15. If it takes 3.2 s for the ball in #14 to reach the top of it’s trip, how high has the ball been thrown?

ans: 57.5 m ‘What an arm!!!!!!!!!!!’16. A graph the has the distance on the x-axis

and the time on the y-axis describes what type of motion?

ans: velocity17. On a velocity to time graph ______ is

described?ans: acceleration

18. How would a constant acceleration of a velocity to time graph look?

ans:

velocity (m/s)

Time (s)

19. What equation would allow you to find the final velocity of an object in free fall given a defined distance?

ans: vf2 = vi

2 + 2gΔd

20. A change in the ________ always indicates a new acceleration.

ans: velocity21. What does a value of -9.8 m/s2 indicate with

respect to free fall?ans: the object is thrown up

22. What would the value be for the acceleration in #21 if the object is dropped?

ans: +9.8 m/s2

23. A ball is dropped. How far will the ball travel in the first 5s in meters?

ans: 122.5 m24.A car gets a rolling start of 1.2 m/s. If the cars

accelerates at 1.5 m/s2 for 54 s, how far will the car travel?

ans: 2251.8 m25. A car accelerates at 0.07 m/s2 for a distance

of 230 m. If the final velocity is measured at 23.2 m/s, what was the initial velocity?

ans: 22.5 m/s