Name: ___________________________________    Date: ______________



1.
A 2-kg block is attached to a horizonal ideal spring with a spring constant of 200 N/m. When the spring has its equilibrium length the block is given a speed of 50 m/s. What is the maximum elongation of the spring?
A.
0
B.
0.05 m
C.
5 m
D.
10 m
E.
100 m


2.
A 8000-N car is traveling at 12 m/s along a horizontal road when the brakes are applied. The car skids to a stop in 4.0 s. How much kinetic energy does the car lose in this time?
A.
4.8 × 104 J
B.
5.9 × 104 J
C.
1.2 × 105 J
D.
5.8 × 105 J
E.
4.8 × 106 J


3.
A particle starts from rest at time t = 0 and moves along the x axis. If the net force on it is proportional to t, its kinetic energy is proportional to:
A.
t
B.
t2
C.
t4
D.
1/t2
E.
none of the above


4.
A small object of mass m starts at rest at the position shown and slides along the frictionless loop-the-loop track of radius R. What is the smallest value of y such that the object will slide without losing contact with the track?
A.
R/4
B.
R/2
C.
R
D.
2R
E.
zero


5.
A 0.50-kg block attached to an ideal spring with a spring constant of 80 N/m oscillates on a horizontal frictionless surface. The total mechanical energy is 0.12 J. The greatest speed of the block is:
A.
0.15 m/s
B.
0.24 m/s
C.
0.49 m/s
D.
0.69 m/s
E.
1.46 m/s


6.
The diagram shows a plot of the potential energy as a function of x for a particle moving along the x axis. The points of stable equilibrium are:
A.
only a
B.
only b
C.
only c
D.
only d
E.
b and d


7.
The center of mass of the system consisting of Earth, the Sun, and the planet Mars is:
A.
closer to the Earth than to either of the other bodies
B.
closer to the Sun than to either of the other bodies
C.
closer to Mars than to either of the other bodies
D.
at the geometric center of the triangle formed by the three bodies
E.
at the center of the line joining the Earth and Mars


8.
A cart loaded with sand slides forward along a horizontal frictionless track. As the cart moves, sand trickles out at a constant rate through a hole in the back of the cart. The acceleration of the cart is:
A.
constant and in the forward direction
B.
constant and in the backward direction
C.
variable and in the forward direction
D.
variable and in the backward direction
E.
zero


9.
A ball hits a wall and rebounds with the same speed, as diagrammed below. The changes in the components of the momentum of the ball are:
A.
Δpx > 0, Δpy > 0
B.
Δpx < 0, Δpy > 0
C.
Δpx = 0, Δpy > 0
D.
Δpx = 0, Δpy < 0
E.
Δpx > 0, Δpy < 0


10.
A man is marooned at rest on level frictionless ice. In desperation, he hurls his shoe to the right at 15 m/s. If the man weighs 720 N and the shoe weighs 4.0 N, the man moves to the left at approximately:
A.
0
B.
2.1 × 10–2 m/s
C.
8.3 × 10–2 m/s
D.
15 m/s
E.
2.7 × 10–3 m/s


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