ex. 1 Consider the following combinations of signs and values for velocity and acceleration of a particle with
respect to a one-dimensional x-axis
Velocity Acceleration
a) +
+
b) +
c) +
0
d) +
e) f) 0
g) 0
+
h) 0
If the object is a car moving on an east-west axis with
east being positive, describe each situation. Which way is it moving? Is it speeding up, slowing down, etc?
ex. 2 An electron moving in a straight line has an initial speed of 3.0 x 105m/s. It speeds up at 8.0 x 1014m/s2.
(a) How long will it take to reach a speed of 5.4 x 105m/s?
(b) How far will it have traveled in this time?
ex. 3 A truck on a straight road starts from rest accelerating at 2.0m/s/s until it reaches a speed of 20m/s. Then
the truck travels for 20s at constant speed until the brakes are applied, stopping the truck in a uniform manner in
an additional 5.0s.
a) How long is the truck in motion?
b) What is the average velocity of the truck for the motion described?
HW4