Examples
1. Does a car speedometer measure speed, velocity, or both?
2. Can an object have a varying speed if its velocity is constant? If yes, give examples
3. When an object moves with constant velocity, does its average velocity
during any time interval differ from its instantaneous velocity at any
instant?
4. Omit
5. Can an object have a northward velocity and a southward acceleration? Explain.
6. Give an example where both the velocity and acceleration are
negative.
7. As a
freely falling object speeds up, what is happening to its acceleration due
to gravity — does it increase, decrease, or stay the same?
8. Can an
object have zero velocity and nonzero acceleration at the same time? Give
examples.
1. Suppose that a ball is dropped from a tower that is 70.0 m high. Assume that positive direction of y is down.
How far will it fall in 3 seconds? Solution
2. Suppose the above ball is thrown downward with an initial velocity of 3.00 m/s. Assume that positive direction of y is down.
What would its speed be after 2 s? Solution
3. Suppose the above ball is thrown upward with an initial velocity of 15.0 m/sec. For this problem, assume that positive direction of y is up.
How high does it go? Solution
4. An Alien spacecraft is ascending vertically over Albuquerque with a speed of 10.0 m/s. At a height of 100 m above the Earth,
an
object (at this height)
is dropped from the craft. How much time does
it take for the object to reach the ground?