Spring 2003 Physics 101 Hour Exam 1
(26 questions)

The grading button and a description of the scoring criteria are at the bottom of this page.Basic questions are marked by a single star *. More difficult questions are marked by two stars **. The most challenging questions are marked by three stars ***.

This exam consists of 26 questions; true-false questions are worth 2 points each, three-choice multiple choice questions are worth 3 points each, five-choice multiple choice questions are worth 6 points each. The maximum possible score is 117. When the exam was given, the mean was 96.2 the median was 102. Click here to see the formula sheet that came with the exam.


QUESTION 1*

This and the following question concern the same physical situation.

Peter goes for a walk along the x-axis. The walk takes him 400 seconds to complete. The graph shows his position X as a function of time.

What was the average velocity of the walk?

(a)   0 m/s
(b)   1 m/s
(c)   2 m/s
(d)   3 m/s
(e)   4 m/s


QUESTION 2*

What was the maximum speed reached during the walk?

(a)   0.5 m/s
(b)   1.0 m/s
(c)   2.0 m/s
(d)   4.0 m/s
(e)   5.0 m/s


QUESTION 3*

This and the following question concern the same physical situation.

This velocity vs. time graph represents the motion of a car.

What was the acceleration of the car at t = 35 s ?

(a)   -2 m/s2
(b)   -1 m/s2
(c)   0 m/s2
(d)   1 m/s2
(e)   2 m/s2


QUESTION 4**

What was the displacement of the car between t = 0 s and t = 40 s?

(a)   0 m
(b)   200 m
(c)   250 m
(d)   350 m
(e)   550 m


QUESTION 5**

This and the following three questions concern the same physical situation.

A 2 kg ball is thrown straight up with an initial velocity of 10 m/s. Your y-coordinate axis is pointing up.

When the ball reaches its maximum altitude the y-component of its acceleration is:

(a)   0
(b)   -g
(c)   +g


QUESTION 6*

What is the maximum altitude reached by the ball?

(a)   1 m
(b)   2.4 m
(c)   5.1 m
(d)   9.8 m
(e)   19.6 m


QUESTION 7*

A second ball, having a mass of 1 kg, is thrown straight up with the same initial velocity as the first ball. Compared to the first ball, the second ball will reach

(a)   the same altitude.
(b)   a smaller altitude.
(c)   a larger altitude.


QUESTION 8**

Now consider two identical balls thrown at the same time. Ball 1 is thrown straight up with an initial speed of V0, and ball 2 is thrown at 45° with the same initial speed V0. Which ball hits the ground first?

(a)   Ball 1.
(b)   Ball 2.
(c)   They both hit the ground at the same time.


QUESTION 9*

This and the following question concern the same physical situation.

A cannon ball is fired at an angle of 30į above horizontal with an initial speed vo = 250 m/s, reaching a maximum height h before hitting the ground.

What is the maximum height h reached by the ball?

(a)   h = 447 m
(b)   h = 796 m
(c)   h = 981 m
(d)   h = 2420 m
(e)   h = 3185 m


QUESTION 10*

Suppose the answer to the above problem is h. If the cannon is fired with an initial speed of 2 vo, the maximum height reached by the ball will be:

(a)   2h
(b)   3h
(c)   4h


QUESTION 11**

Suppose a box having a mass M sits on the floor of an elevator that is moving upward but is slowing down. Compare the weight of the box (Mg) to the magnitude of the normal force exerted by the elevator floor on the box (FN).

(a)   FN < Mg
(b)   FN = Mg
(c)   FN > Mg


QUESTION 12**

Three forces act on a ball of mass 2 kg as shown in the figure below. What is the magnitude of the acceleration of the ball? (There is no gravity in this problem.)

(a)   100 m/s2
(b)   200 m/s2
(c)   300 m/s2
(d)   400 m/s2
(e)   500 m/s2


QUESTION 13*

This and the following question concern the same physical situation.

A box of mass M slides down a frictionless inclined plane that makes an angle θ with the horizontal.

What is the magnitude of the normal force acting on the box?

(a)   M g
(b)   M g cos(θ)
(c)   M g sin(θ)


QUESTION 14*

What is the magnitude of the acceleration of the box?

(a)   g
(b)   g cos(θ)
(c)   g sin(θ)


QUESTION 15*

A block of mass M rests on a horizontal frictionless tabletop. A string is attached to this block, passes over a pulley, and attaches to an identical block that hangs over the edge as shown in the figure. Since gravity pulls the hanging block downward, the blocks accelerate as shown.

Which one of the following best describes the tension in the string?

(a)   T = Mg
(b)   T > Mg
(c)   T < Mg


QUESTION 16*

City B is directly north of City A, and a highway runs between them. You are piloting a plane that flies with a speed of VP,A = 200 km/h relative to the air. On a day when the wind is blowing from west to east at VA,G = 100 km/h relative to the ground, what direction θ do you need to point the nose of the plane such that you stay directly above the highway as you fly from A to B?

(a)   θ = 5° west of north
(b)   θ = 10° west of north
(c)   θ = 20° west of north
(d)   θ = 30° west of north
(e)   θ = 45° west of north


QUESTION 17*

A car is moving to the right. A pendulum is suspended from the ceiling and hangs as shown in the figure. What can we say about the speed of the car?

(a)   The car has a constant speed.
(b)   The carís speed is increasing.
(c)   The carís speed is decreasing.


QUESTION 18*

This and the following question concern the same physical situation.

A block of mass M = 4.0 kg is free to move on a horizontal frictionless surface, and is pulled with a rope that makes an angle of 30° with the horizontal as shown in the drawing below. The tension in the rope is 25 N. What is the acceleration of the block?

(a)   4.41 m/s2
(b)   7.81 m/s2
(c)   2.24 m/s2
(d)   3.54 m/s2
(e)   5.41 m/s2


QUESTION 19**

What is the magnitude of the normal force, FN, that acts on the block?

(a)   FN = Mg
(b)   FN < Mg
(c)   FN > Mg


QUESTION 20*

This and the following question concern the same physical situation.

You apply a horizontal force of 500 N to a 100 kg box on a horizontal floor, and you observe that the box has an acceleration of a = 4 m/s2.

What is the kinetic coefficient of friction μK between the box and the floor?

(a)   μK = 0.10
(b)   μK = 0.15
(c)   μK = 0.20
(d)   μK = 0.25
(e)   μK = 0.30


QUESTION 21*

If the mass is doubled to 200 kg, but the applied force and the coefficient of friction remain the same, what will the acceleration anew of the box be?

(a)   anew = 2 m/s2
(b)   anew > 2 m/s2
(c)   anew < 2 m/s2


QUESTION 22*

A sled is traveling at 3 m/s along a horizontal stretch of snow. The kinetic coefficient of friction between the sled and the snow is μK = 0.050. How far does the sled slide before stopping?

(a)   5.1 m
(b)   7.7 m
(c)   8.5 m
(d)   9.2 m
(e)   11.6 m


QUESTION 23*

This and the following question concern the same situation.
For these two questions you can ignore the effect of gravity.

A physics student ties a 0.5 kg rock to the end of a string and twirls it in a horizontal circle of radius 2 m. If the speed of the rock is 10 m/s, what is the tension T in the string?

(a)   T = 25 N
(b)   T = 50 N
(c)   T = 75 N
(d)   T = 100 N
(e)   T = 200 N


QUESTION 24*

If the mass of the rock, the speed of the rock, and the radius of the circle, are all doubled, how will the new tension TNEW compare with the tension T found in the above problem?

(a)   TNEW = 2T
(b)   TNEW = 4T
(c)   TNEW = 8T


QUESTION 25*

This and the following question concern similar situations.

Suppose the distance of the satellite from the center of the earth is R = 108 m. Assuming that G = 6.7 × 10-11 N-m2/kg2 and that the mass of the earth is ME = 5.98 × 1024 kg, what is the speed of the satellite?

(a)   1200 m/s
(b)   1650 m/s
(c)   2000 m/s
(d)   2200 m/s
(e)   2700 m/s


QUESTION 26*

If the satellite instead orbited a new planet whose mass was half of the Earths mass, but the radius of the orbit was the same as in the above question, how would the speed of the satellite around this new planet be different from the speed in the above question.

(a)   The speed would be the same.
(b)   The speed would be bigger.
(c)   The speed would be smaller.