Principles of Physics A Calculus-Based Text, 5th Edition Volume 1 And 2 By Raymond A – Test Bank

Principles of Physics A Calculus-Based Text, 5th Edition Volume 1 And 2 By Raymond A – Test Bank

Chapter 6—Energy of a System

MULTIPLE CHOICE

1. A constant force of 12 N in the positive x direction acts on a 4.0-kg object as it moves from the origin to the point m. How much work is done by the given force during this displacement?
a. +60 J
b. +84 J
c. +72 J
d. +48 J
e. +57 J

ANS: C PTS: 2 DIF: Average

2. A 5.0-kg object is pulled along a horizontal surface at a constant speed by a 15-N force acting 20 above the horizontal. How much work is done by this force as the object moves 6.0 m?
a. 78 J
b. 82 J
c. 85 J
d. 74 J
e. 43 J

ANS: C PTS: 2 DIF: Average

3. A 2.0-kg projectile moves from its initial position to a point that is displaced 20 m horizontally and 15 m above its initial position. How much work is done by the gravitational force on the projectile?
a. +0.29 kJ
b. 0.29 kJ
c. +30 J
d. 30 J
e. 50 J

ANS: B PTS: 2 DIF: Average

4. How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?
a. 0.22 kJ
b. 0.20 kJ
c. 0.24 kJ
d. 0.27 kJ
e. 0.31 kJ

ANS: B PTS: 2 DIF: Average

5. A 2.5-kg object falls vertically downward in a viscous medium at a constant speed of 2.5 m/s. How much work is done by the force the viscous medium exerts on the object as it falls 80 cm?
a. +2.0 J
b. +20 J
c. 2.0 J
d. 20 J
e. +40 J

ANS: D PTS: 2 DIF: Average

6. The same constant force is used to accelerate two carts of the same mass, initially at rest, on horizontal frictionless tracks. The force is applied to cart A for twice as long a time as it is applied to cart B. The work the force does on A is WA; that on B is WB. Which statement is correct?
a. WA = WB.
b. WA = WB.
c. WA = 2 WB.
d. WA = 4 WB.
e. WB = 2 WA.

ANS: D PTS: 1 DIF: Easy

7. Carts A and B have equal masses and travel equal distances on straight frictionless tracks while a constant force F is applied to A, and a constant force 2F is applied to B. The relative amounts of work done by the two forces are related by
a. WA = 4 WB.
b. WA = 2 WB.
c. WA = WB.
d. WB = 2 WA.
e. WB = 4 WA.

ANS: D PTS: 1 DIF: Easy

8. When a crate of mass m is dragged a distance d along a surface with coefficient of kinetic friction k, then dragged back along the same path to its original position, the work done by friction is
a. 0.
b. kmgd.
c. +kmgd.
d. 2kmgd.
e. +2kmgd.

ANS: D PTS: 1 DIF: Easy

9. Planets go around the sun in elliptical orbits. The highly exaggerated diagram below shows a portion of such an orbit and the force on the planet at one position along that orbit. The planet is moving to the right. F|| and are the components of the force parallel (tangential) and perpendicular (normal) to the orbit. The work they do is W|| and . At the position shown

a. W|| slows the planet down; speeds it up.
b. W|| slows the planet down; does no work on it.
c. W|| speeds the planet up; does no work on it.
d. W|| speeds the planet up; slows it down.
e. W|| does no work on it; speeds the planet up.

ANS: B PTS: 2 DIF: Average