Ch#1: motion in straight line

1. Al-Farabi College
Name: …………………
General Physics 101 PHYS
Assignment II
Instructor: Dr. Said Moh’d Azar
1. The position of a pinewood derby car was observed at various times; the results
are summarized in the following table. Find the average velocity of the car for (a)
the first second, (b) the last 3 s, and (c) the entire period of observation.
2.
A particle starts from rest and accelerates as shown in figure below. Determine (a)
the particle’s speed at t = 10.0 s and at t = 20.0 s, and (b) the distance traveled in
the first 20.0 s.
3. A truck covers 40.0 m in 8.50 s while smoothly slowing down to a final speed of
2.80 m/s. (a) Find its original speed. (b) Find its acceleration.

2. 4. A 745i BMW car can brake to a stop in a distance of 121 ft. from a speed of 60.0
mi/h. To brake to a stop from a speed of 80.0 mi/h requires a stopping distance of
211 ft. What is the average braking acceleration for (a) 60 mi/h to rest, (b) 80 mi/h
to rest, (c) 80 mi/h to 60 mi/h? Express the answers in mi/h/s and in m/s2.
5. A ball is thrown directly downward, with an initial speed of 8.00 m/s, from a
height of 30.0 m. After what time interval does the ball strike the ground?
6. A freely falling object requires 1.50 s to travel the last 30.0 m before it hits the
ground. From what height above the ground did it fall?

3. 7. An automobile moving along a straight track changes its velocity from 40 m/s to
80 m/s in a distance of 200 m. What is the (constant) acceleration of the vehicle
during this time?
8. An object moving on the x axis with a constant acceleration increases its x
coordinate by 80 m in a time of 5.0 s and has a velocity of +20 m/s at the end of
this time. Determine the acceleration of the object during this motion.
9. A ball thrown vertically from ground level is caught 3.0 s later by a person on a
balcony which is 14 m above the ground. Determine the initial speed of the ball.
10. A particle confined to motion along the x axis moves with constant acceleration
from x = 2.0 m to x = 8.0 m during a 2.5-s time interval. The velocity of the
particle at x = 8.0 m is 2.8 m/s. What is the acceleration during this time interval?