A 2500-kg truck moving at 10.00 m/s strikes a car waiting at a traffic light, hooking bumpers. The two continue to move together at 6.00 m/s. What was the mass of the struck car?
a. 1730 kg
c. 1200 kg
b. 1670 kg
d. 1070 kg
[Ques. 2] If body M, with a positive charge, is used to charge body N by induction, what will be the nature of the charge left on the latter?
a. must be positive
b. must be equal in magnitude to that on M
c. must be negative
d. must be greater in magnitude than that on M
[Ques. 3] A billiard ball is moving in the x direction at 40.0 cm/s and strikes another billiard ball moving in the y direction at 30.0 cm/s. As a result of the collision, the first ball moves at 50.0 cm/s, and the second ball stops. What is the change in kinetic energy of the system as a result of the collision?
a. 0
c. some negative value
b. some positive value
d. No answer above is correct.
[Ques. 4] Which of the following best characterizes electrical insulators?
a. high tensile strength
c. good heat conductors
b. charges on the surface don't move
d. electric charges move freely
[Ques. 5] A billiard ball is moving in the x direction at 30.0 cm/s and strikes another billiard ball moving in the y direction at 40.0 cm/s. As a result of the collision, the second ball moves at 50.0 cm/s, and the first ball stops. In what final direction does the second ball move?
a. in the x direction
b. at an angle of 45.0o ccw from the x direction
c. at an angle of 53.1o ccw from the x direction
d. Such a collision cannot happen.
[Ques. 6] Which of the following best characterizes electrical conductors?
a. high tensile strength
c. electric charges move freely
b. poor heat conductors
d. low mass density
[Ques. 7] An object of mass m moving at speed v strikes and object of mass 2m which had been at rest. The first object bounces backward along its initial path at speed v. Is this collision elastic, and if not, what is the change in kinetic energy of the system?
a. The collision is elastic. b. The kinetic energy decreases by mv2.
c. The kinetic energy decreases by 1/2 mv2.
d. The kinetic energy increases by mv2.
[Ques. 8] Of the following substances, which one contains the highest density of free electrons?
a. glass
c. iron
b. hard rubber
d. amber
[Ques. 9] A uranium nucleus (mass 238 units) at rest decays into a helium nucleus (mass 4.0 units) and a thorium nucleus (mass 234 units). If the speed of the helium nucleus is 1.8 106 m/s, what is the speed of the thorium nucleus?
a. 1.0 104 m/s
c. 3.6 104 m/s
b. 3.1 104 m/s
d. 4.1 104 m/s
[Ques. 10] An uncharged conductor is supported by an insulating stand. I pass a positively charged rod near the left end of the conductor, but do not touch it. The right end of the conductor will be:
a. neutral.
c. attracted. b. positive.
d. negative.
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