PHYS Exam II - Chapter 4

Velocity is defined as
a) rate of change of position with time
b) position divided by time
c) rate of change of acceleration with time
d) a speeding up or slowing down
e) change of position

a) rate of change of position with time

Which of the following is a vector quantity?
a) mass
b) density
c) speed
d) temperature
e) none of these

e) none of these

Acceleration is defined as
a) rate of change of position with time
b) speed divided by time
c) rate of change of velocity with time
d) a speeding up or slowing down
e) change of velocity

c) rate of change of velocity with time

Which of the following is NOT an example of accelerated motion?
a) vertical component of projectile motion
b)circular motion at constant speed
c) a swinging pendulum
d) earth's motion about sun
e) horizontal component of projectile motion

e) horizontal component of projectile motion

Which of the following is a scalar quantity?
a) speed
b) velocity
c) displacement
d) acceleration
e) none

a) speed

Two bodies are falling with negligible air resistance, side by side, above a horizontal plane. If one of the bodies is given an additional horizontal acceleration during its descent, it:
a) strikes the horizontal plane at the same time as the other body
b

a) strikes the horizontal plane at the same time as the other body

The velocity of a projectile equals its initial velocity added to
a) a constant horizontal velocity
b) a constant vertical velocity
c) a constantly increasing horizontal velocity
d) a constantly increasing downward velocity
e) a constant velocity directed

d) a constantly increasing downward velocity

A bullet shot horizontally from a gun
a) strikes the ground much later than one dropped vertically from the same point at the same instant
b) never strikes the ground
c) strikes the ground at approximately the same time as one dropped vertically from the

c) strikes the ground at approximately the same time as one dropped vertically from the same point at the same instant

A bomber flying in level flight with constant velocity releases a bomb before it is over
the target. Neglecting air resistance, which one of the following is NOT true?
a) The bomber is over the target when the bomb strikes.
b) The acceleration of the bomb

c) The horizontal velocity of the plane equals the vertical velocity of the bomb when it hits the target

An object is shot from the back of a railroad flatcar moving at 40 km/h on a straight horizontal road. The launcher is aimed upward, perpendicular to the bed of the flatcar. The object falls:
A) in front of the flatcar
B) behind the flatcar
C) on the truc

C) on the truck

Which one of the following statements concerning the displacement of an object is FALSE?
a) displacement is a vector quantity that points from the initial position of an object to its final position
b) the magnitude of an object's displacement is always e

b) the magnitude of an object's displacement is always equal to the distance it traveled from its initial position to its final position

Which one of the following quantities is an object's displacement divided by the elapsed time of the displacement?
a) avg. velocity
b) instantaneous velocity
c) average displacement
d) average acceleration
e) instantaneous acceleration

a) avg. velocity

Complete the following statement: The direction of the instantaneous velocity of a particle is
a) tangent to the path of particle
b) the same as the direction of the average velocity vector
c) perpendicular to the path of the particle
d) the same as the d

a) tangent to the path of particle

A truck drives south for 1.8 km in 2.0 minutes. Then, the truck turns and drives due west for 1.8 km in 2.0 minutes. Which one of the following statements is true?
a) the avg. speed for the two segments is the same. the avg. velocity for the two segments

c) the avg. speed for the two segments is the same. the avg. velocity for the two segments is not the same.

Which one of the following quantities is the change in object's velocity divided by the elapsed time as the elapsed time becomes very small?
a) avg. v
b) inst. v
c) avg. displacement
d) avg. acceleration
e) inst. acceleration

e) inst. acceleration

A football is kicked at an angle 25 with respect to the horizontal. Which one of the following statements best describes the acceleration of the football during this event if air resistance is neglected?
*
a is for acceleration
*
a) a is 0 m/s� at all tim

e) a is 9.8 m/s� at all times

A baseball is hit upward and travels along a parabolic arc before it strikes the ground. Which one of the following statements is necessarily true?
a) v of the ball is a maximum when the ball is at the highest point in the arc
b) x-component of the v of t

b) x-component of the v of the ball is the same throughout the ball's flight

Two cannons are mounted on a high cliff. Cannon A fires balls with twice the initial velocity of cannon B. Both cannons were aimed horizontally and fired. How does the horizontal range of cannon A compare to that of cannon B.
a) the range for both will be

e) range of the cannon B is about 0.5 times that of cannon A

Which one of the following statements concerning the range of a football is true if the football is kicked at an angle ? with an initial speed v?
a) range is independent of int. speed
b) range is only dependent on the int. speed
c) range is independent of

e) range is dependent on both int. speed and ?

In projectile motion,
a) the horiz. motion depends on the vert. motion
b) the vert. motion depend son the horiz. motion
c) the horiz. acceleartion depends on the vertical acceleration
d) the horiz. motion and the vert. motion are independent of each other

d) the horiz. motion and the vert. motion are independent of each other

An airplane is flying horizontally at a constant velocity when a package is dropped from its cargo bay. Assuming no air resistance, which one of the following statements is correct?
a) The package follows a curved path that lags behind the airplane.
b) Th

d) The package follows a curved path, but it is always vertically below the airplane.

A steel ball is tied to the end of a string and swung in a vertical circle at constant speed. Complete the following statement: The direction of the acceleration of the ball is always
a) perpendicular to the circle
b) towards the center of the circle
c) t

b) towards the center of the circle

A steel ball is tied to the end of a string and swung in a vertical circle at constant speed. Complete the following statement: The direction of the instantaneous velocity of the ball is always:
a) perpendicular to the circle
b) towards the center of the

c) tangent to the circle

In 2-D motion in the x-y plane, the x part of the motion and the y-part of the motion are independent
a) only if there is no a in either direction
b) only if these is no a in one of the direction
c) only if there is an a in both directions
d) whether or n

d) whether or not there is an a in any direction

A bicyclist is riding at a constant speed along a horizontal, straight-line path. The rider throws a ball straight up to a height a few meters above her head. Ignoring air resistance, where will the ball land?
a) in front of the rider
b) behind the rider

c) in the same hand that threw the ball

Packages A and B are dropped from the same height simultaneously. Package A is dropped from an airplane that is flying due east at constant speed. Package B is dropped from rest from a helicopter hovering in a stationary position above the ground. Ignorin

b) A and B reach the ground at the same time, and they have the same v in the vert. direction

A motorcyclist is riding along a mountain trail that runs parallel to a road below. In fact the trail is 6 meters above the road. The motorcyclist then notices a flat bed truck directly below moving at the same speed and decides to drive off the trail, wi

c) The motorcycle would land on the flatbed of the truck as before.

A motorcyclist is riding along a mountain trail that runs parallel to a road below. In fact the trail is 6 meters above the road. The motorcyclist then notices a flat bed truck directly below moving at the same speed and decides to drive off the trail, wi

a) The motorcycle would land behind the truck.