Speed is
a. measure of how fast something is moving.
b. Always measured in terms of a unit of distance divided by a unit of time.
c. The distance covered per unit of time.
d. All of the above.
e. None of the above.
c. The distance covered per unit of time.
One possible unit of speed is
a. miles per hour
b. Light years per century
c. Kilometers per hour
d. All of the above
e. None of the above.
d. All of the above
When you look at the speedometer in a moving car, you can see the car's
A) average distance traveled.
B) Iinstantaneous acceleration
C) average speed.
D) instantaneous speed.
E) average acceleration.
d. instantaneous speed.
Acceleration is defined as the CHANGE in
a. time it takes to move from one place to another place.
b. velocity of an object.
c. distance divided by the time interval.
d. velocity divided by the time interval.
e. time it takes to move from one speed to ano
d. velocity divided by the time interval
Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which of the following is NOT true?
a. You and the car are accelerating.
b. Your acceleration is constantly changing.
c. Your velocity is constant.
c. Your velocity is constant.
A unit of acceleration is meters per second.
a. true
b. false
b. false
A car starts from rest and after 7 seconds it is moving at 42 m/s. What is the car's average acceleration?
a. 0.17 m/s^2
b. 1.67 m/s^2
c. 6 m/s^2
d. 7 m/s^2
e. none of the above.
c. 6 m/s^2 (FORMULA: a = v/t)
As an object falls freely in a vacuum, its
a. velocity increases.
b. acceleration increases.
c. both A and B.
d. none of the above.
a. velocity increases (acceleration is constant 10 m/s^2)
In the absence of air resistance, objects fall a constant
a. speed.
b. velocity.
c. acceleration.
d. distances each successive second.
e. all of the above.
c. acceleration
A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball the instant before it is caught would be
a. less than the speed it had when thrown upwards.
b. more than the speed it had wehn thrown upwa
c the same as the speed it had when thrown upwards.
Suppose an object is in free fall. Each second the object falls
a. the same distance as in the second before.
b. a larger distance that in the second before.
c. with the same instantaneous speed.
d. with the same average speed.
e. none of above
b. a larger distance than in the second before.
If you drop a feather and a coin at the same time in a tube filled with air, which will reach the bottom of the tube first?
a. The feather
b. Neither-they will reach the bottom at the same time.
c. The coin
c. The coin (only with air!!)
Consider drops of water leaking from a water faucet. As the drops fall they
a. remain at a relatively fixed distance from each other.
b. get farther apart.
c. get closer together.
get farther apart.
A ball is thrown into the air. At the highest point, the ball has zero velocity and zero acceleration
a. true
b. false
a. true
The hang time (time one's feet are off the ground in a jump) for most athletes is
a. less than 1 second.
b. considerably more than 1 second
c. about 1 second.
d. slightly more than 1 second.
a. less than 1 second.
When a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration
a. varies with body orientation
b. depends on launch speed.
c. is usually greater for taller players (but not always).
d. depends on all the above.
e
e. is g; no more, no less.
Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is
a. 30 km/h
b. 60 km/h
c. 180 km/h
d. 360 km/h
e. 540 km/h
60 km/h (FORMULA: v = d/t)
Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second from 40/km/h to 45 km/hr
a. 5 km/h.s
b. 10 km/h.s
c. 35 km/h.s
d. 40 km/h.s
e. 45 km/h.s
a. 5 km/h.s (FORMULA: a = change v/change t) (therefore change v = 10 km/h change t = 2s)