Physics 201 Exam 1, Chapter 2

The coordinate of an object is given as a function of time by x=4t^2-3t^3, where x is in meters and t is in seconds. It's average acceleration over the interval from t-0 to t=2 is

-10m/s^2

Over a short interval near time t=0 the coordinate of an automobile in meters is given by x(t) = 27t-4t^3, where t is in seconds. At the end of 1s the acceleration of the auto is:

-24m/s^2

Starting at time t=0 an object moves along a straight line with velocity in m/s given by v(t)=98-2t^2, where t is in seconds. When it momentarily stops its acceleration is:

-28m/s^2

Starting at time t=0, an object moves along a straight line. Its coordinate in meters is given by x(t)=75t-1t^3, where t is in seconds. When it momentarily stops its acceleration is:

-30m/s^2

The coordinate of an object is given as a function of time by x=t7-3t^2, where x is in meters and t is in seconds. It's average velocity over the interval from t=0 to t=4s is:

-5m/s

An object is thrown straight donw with an initial speed of 4m/s from a window which is 8m above the ground. The time it takes the object to reach the ground is:

.93 s

A car starts from hither, goes 50km in a straight line to Yon, immediately turns around, and returns to Hither. The time for this round trip is 2hours. The magnitude of the average velocity of the car for this round trip is:

0

The velocity of an object is given as a function of time by v=4t-3t^2, where v is in m/s and t is in seconds. It's average velocity over the interval from t=0 to t=2s is:

0

The coordinate of a particle in meters is given by x(t)=16t-3t^3, where the time t is in seconds. the particle is momentarily at rest at t=

1.3s

Two automobiles are 150 km apart and traveling towards each other. One automobile is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet?

1.5

One object is thrown vertically upward with an velocity of 100 m/s and another object with an initial velocity of 10 m/s. The maximum height reached by the first object will be ______ that of the other.

100 times

At a stop light, a truck traveling at 15 m/s passes a car as it starts from rest. The truck travels at a constant velocity and the car accelerates at 3 m/s^2. How much time does the car take to catch up to the truck?

10s

At a location where g= 9.8m/s^2, an object is thrown vertically down with an initial speed of 1 m/s. After 5s the object will have traveled:

127.5m

An abject is thrown vertically upward at 35 m/s. Taking g =10 m/s^2, the velocity of the object 5s later is:

15 m/s down

An object is released from rest. How far does it fall during the seconds of its fall?

15m

A stone is thrown vertically upward with an initial of 19.5 m/s. It will rise to a maximum height of:

19.4 m

A car, initially at rest, travels 20cm in 4s along a straight line with constant acceleration. The acceleration of the car is:

2.4 m/s^2

A stone is released from a balloon that is descending at a constant speed of 10 m/s. Neglecting air resistance, after 20 s the speed of the stone is:

206 m/s

A car starts from rest and goes down a slope with a constant acceleration of 5m/s^2. After 5s the car reaches the bottom of the hill. It's speed at the bottom of the hill, in meters/second, is?

25

Over a short interval, starting at time t=0, the coordinate of an automobile in meters is given by x(t) = 27t-4t^3, where t is in seconds. The magnitude of the initial (at t=o) velocity and acceleration of the auto respectively are:

27 m/s, 0

A heavy ball falls freely, starting from rest. Between the third and fourth second of time it travels a distance of:

34.3m

The graph represents the straight line motion of car. How far does the car travel between t=2s and t-5s

36 m

A ball rolls up a slope. At the end of three seconds its velocity is 20cm/s; at the end of eight seconds its velocity is 0. What is the average acceleration from the third to the eighth second?

4.0 cm/s^2

A baseball is hit straight up and is caught by the catcher 2s later. The maximum height of the ball during the interval is:

4.9m

A projectile is shot vertically upward with a given initial velocity. It reaches a maximum height of 100m. If on a second shot, the initial velocity is doubled then the projectile will reach a maximum height of:

400 m

An object is thrown straight up from ground level with a speed of 50m/s. If g=10m/s^2 its distance about ground level 1s later is?

45m

How far does a car travel in 6s if its initial velocity is 2m/s and its acceleration is 2 m/s^2 in the forward direction?

48 m

A racing car traveling with constant acceleration increases its speed from 10m/s to 50m/s over a distance of 60cm. How long does this take?

4s

A car starts from Hither, goes 50 km in a straight line to Yon, immediately turns around, and returns to Hither. The time for this round trip is 2 hours. The average speed of the car for this round trip is:

50 km.h

A car travels 40km at an average speed of 80km/h and then travels 40 km at an average speed of 40km/h. The average speed of the car for this 80km trip is:

53 km/h

An object with an initial velocity of 12 m/s west experiences a constant acceleration of 4m/s^2 west for 3 seconds. During this time the object travels a distance of?

54 m

At time t=0 a car has a velocity of 16m/s. It slows down with an acceleration given by -.5t, in m/s^2 for t in seconds. At the end of 4s it has traveled?

59m

A stone is released from rest from the edge of a building roof 190m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is:

61 m/s

An object starts form rest at the origin and moves along the x-axis with a constant acceleration of 4m/s^2. Its average velocity as it goes from x=2. to x=8m is:

6m/s

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in:

6s

An object dropped from the window of a tall building hits the ground in 12 s. If its acceleration is 9;8 m/s^2, the height of the window above the ground is:

706 m

A car moving with an initial velocity of 25m/s north has a constant acceleration of 3m/s^2 south.After 6 seconds its velocity will be:

7m/s north

At time t=0 a car has a velocity of 16m/s. It slows down with an acceleration given by -.5t in m/s^2 for t in seconds. By the time it stops it has traveled?

85m

At time t-0 a car has a velocity of 16m/s. It slows down with an acceleration given by -.5t, in m/s^2 for t in seconds. It stops at t=?

8s

As a rocket is accelerating vertically upward at 9.8m/s^2 near earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s^2) of the projectile is:

9.8 down

Of the following situations, which one is impossible?

A body having constant velocity and a variable acceleration

Which of the following five coordinate versus time graphs represents the motion of an object whose speed is increasing?

A. Curve upwards

Each of the four particles move alone an x-axis. Their coordinates (m) as function of time (s) are given by..... Which of these particles is speeding up for t>0?

All four

An elevator is moving upward with constant acceleration. The dashed curve shows the position y of the ceiling of the elevator as a function of the time t. At the instant indicated by the dot, a bolt breaks loose and drops from the ceiling. Which curve best represents the position of the bolt as a function of time?

B

An object is dropped from rest. Which the following five graphs correctly represents its motion? The positive direction is taken to be downward.

B

Which of the following five coordinate versus time graphs represents the motion of an object moving with a constant nonzero speed?

B downward straight line

A stone is dropped from cliff. The graph (carefully note the axes) which best represents its motion while it falls is:

C

An object is thrown vertically into the air. Which of the following five graphs represents the velocity (v) of the object as a function of the time (t)? The positive direction is taken to be upward.

C downward straight line

Which of the following five acceleration versus time graphs is correct for an object moving in a straight line at a constant velocity of 20m/s

E straight line on x axis

A car accelerates from rest on a straight road. A short time later, the car decelerates to a stop and then returns to its original position in a similar manner, by speeding up and then slowing to a stop. Which of the following five coordinate versus time graphs best describes the motion?

E. Small curvew

The position y of a particle moving along the y axis depends on the time t according to the equation y=at-bt^2. The dimensions of the quantities a and b are respectively:

L/T,L/T^2

The average speed of a moving object during a given interval of time is always:

The distance covered during the time interval divided by the time interval.

The diagram shows a velocity-time graph for a car moving in a straight line. At point P the car must be:

accelerating

The acceleration of an object, starting from rest, is shown in graph below. Other than at t=0, when is the velocity of the object equal to zero?

at no other time less than or equal to 5s

A drag racing car starts from rest at t=0 and moves along a straight line with velocity given by v=bt^2 where b is a constant. The expression for the distance traveled by this car from its position at t=0 is:

bt^3/3

The coordinate-time graph of an object is a straight line with a positive slope. The object has:

constant velocity

The area under a velocity-time graph represents:

displacement

A ball is in free fall. Its acceleration is?

downward during both ascent and descent.

A baseball is thrown vertically into the air. The acceleration of the ball at its high point is:

g, down

An object is thrown vertically upward with a certain initial velocity in a world where the acceleration due to gravity is 19.6 m/s^2. The height to which it rises is ___ that to which the object would rise if thrown upward with the same initial velocity on the earth. Neglect friction.

half

Consider the following five graphs (note the aces carefully). Which of these represents motion at constant speed?

i and iv only

An object is shot vertically upward. while it is rising:

its velocity is upward and its acceleration is downward

Throughout a time interval, while the speed of a particle increases as it moves along the x-axis, its velocity and acceleration might be:

negative and negative, respectively

A particle moves along the x-axis according to the equation x=6t^2, where x is in meters and t is in seconds. Therefore:

none of the above

A particle moves on the x-axis. when its acceleration is positive and increasing:

none of the above must be true

An object is thrown straight up from ground level with a speed of 50m/s. If g=10m/s^2 its distance above ground level 6s later is:

none of these

Each of four particles move along an x axis. Their coordinates (in meters) as functions of time (in seconds) are given by....... Which of these particles have constant acceleration?

only 3 and 4

A ball is in free fall. Upward is taken to be the positive direction. The displacement of the ball during a short time interval is:

positive during ascent and negative during descent

An object has a constant acceleration of 3 m/s^2. The coordinate versus time graph for this object has a slope.

that increases with time

A feather, initially at rest, is released in a vacuum 12 m above the surface of the earth. Which of the following statements is correct?

the acceleration of the feather remains constant during the fall

Displacement can be obtained from:

the area under a velocity-time graph

which of the following statements is correct for an object released from rest?

the average velocity during the first second of time is 4.9 m/s

The diagram represents the straight line motion of a car. Which of the following statements is true?

the car accelerates at 6m/s^2 for the first 2 s

A free falling body has a constant acceleration of 9.8 m/s^2. This means:

the speed of the body increases by 9.8 m/s^2 during each second

The diagram shows a velocity-time graph for a car moving in a straight line. At point Q the car must be:

traveling in the reverse direction to that at point p

A particle moves along the x acis from xi to xf. Of the following values of the initial and final coordinates, which results in the displacement with the largest magnitude?

xi=-4m, xf= 4m

A particle moves alone the x axis from xi to xf. Of the following values of the initial and final coordinates, which results in a negative displacement?

xi=-4m, xf=-8m