Physics- Chapters 5-8

A child moving at constant velocity carries a 2 N ice-cream cone 1 m across a level surface. What is the net work done on the ice-cream cone? a. 0 J b. 0.5 J c. 2 J d. 20 J

A. 0 J

Which of the following energy forms is associated with an object due to its position? a. Potential b. Positional c. Total d. Kinetic

A. Potential

Work is done when a. The displacement is not zero b. The displacement is zero c. The force is zero d. The force and displacement are perpendicular

A. The displacement is not zero

If the only force acting on an object is friction during a given physical process, which of the following assumptions must be made in regard to the object's kinetic energy? a. The kinetic energy decreases b. The kinetic energy increases c. The kinetic energy remains constant d. The kinetic energy decreases and then increases

A. The kinetic energy decreases

The magnitude of the component of the force that does the work is 43.0 N. How much work is done on a bookshelf being pulled 5.00 m at an angle of 37.0° from the horizontal? a. 172 J b. 215 J c. 129 J d. 792 J

B. 215 J

Which of the following energy forms is NOT involved in hitting a tennis ball? a. Kinetic energy b. Chemical Potential energy c. Gravitational Potential energy d. Elastic Potential energy

B. Chemical Potential energy

Which of the following energy forms is stored in any compressed or stretched object? a. nonmechanical energy b. elastic potential energy c. gravitational potential energy d. kinetic energy

B. Elastic potential energy

A force does work on an object if a component of the force a. is perpendicular to the displacement of the object. b. is parallel to the displacement of the object. c. perpendicular to the displacement of the object moves the object along a path that returns the object to its starting position. d. parallel to the displacement of the object moves the object along a path that returns the object to its starting position.

B. Is Parallel to the displacement of the object.

The main difference between kinetic energy and potential energy is that a. kinetic energy involves position and potential energy involves motion. b. kinetic energy involves motion and potential energy involves position. c. although both energies involve motion, only kinetic involves position. d. although both energies involve position, only potential involves motion.

B. Kinetic energy involves motion and potential energy involves position

A horizontal force of 200 N is applied to move a 55 kg television set across a 10 m level surface. What is the work done by the 200 N force on the television set? a. 4000 J b. 5000 J c. 2000 J d. 6000 J

C. 2000 J

A hill is 100 m long and makes an angle of 12° with the horizontal. As a 50 kg jogger runs up the hill, how much work does gravity do on the jogger? a. 50 000 J b. 10 000 J c. -10 000 J d. 0.0 J

C. -10 000 J

What is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s? a. 54.0 J b. 87.0 J c. 108 J d. 216 J

C. 108 J

A worker pushes a wheelbarrow with a horizontal force of 50.0 N over a level distance of 5.0 m. If a frictional force of 43 N acts on the wheelbarrow in a direction opposite to that of the worker, what net work is done on the wheelbarrow? a. 250 J b. 0.0 J c. 35 J d. 10.0 J

C. 35 J

A 1.00 x 10^3 kg sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the average power output of the automobile engine? a. 20.8 kW b. 30.3 kW c. 41.7 kW d. 52.4 kW

C. 41.7 kW

A flight attendant pulls a 50.0 N flight bag a distance of 250.0 m along a level airport floor at a constant speed. A 30.0 N force is exerted on the bag at an angle of 50.0° above the horizontal. How much work is done on the flight bag? a. 12 500 J b. 7510 J c. 4820 J d. 8040 J

C. 4820 J

Which of the following energy forms is associated with an object due to its position relative to Earth? a. Potential energy b. Elastic potential energy c. Gravitational potential energy d. Kinetic energy

C. Gravitational potential energy

If both the mass and the velocity of a ball are tripled, the kinetic energy of the ball is increased by a factor of a. 3 b. 6 c. 9 d. 27

D. 27

A 3.00 kg toy falls from a height of 10.0 m. Just before hitting the ground, what will be its kinetic energy? (Disregard air resistance. g = 9.81 m/s2.) a. 98.0 J b. 0.98 J c. 29.4 J d. 294 J

D. 294 J

Which of the following energy forms is involved in winding a pocket watch? a. Electrical energy b. Nonmechanical energy c. Gravitational Potential energy d. Elastic Potential energy

D. Elastic Potential energy

Which of the following energy forms is associated with an object in motion? a. Potential energy b. Elastic potential energy c. Nonmechanical energy d. Kinetic energy

D. Kinetic energy

A construction worker pushes a wheelbarrow 5.0 m with a horizontal force of 50.0 N. How much work is done by the worker on the wheelbarrow? a. 10 J b. 1250 J c. 250 J d. 55 J

c. 250 J

Which form of energy is involved in weighing fruit on a spring scale? a. kinetic energy b. nonmechanical energy c. gravitational potential energy d. elastic potential energy

d. Elastic potential energy

The equation for determining gravitational potential energy is PEg = mgh. Which factor(s) in this equation is (are) NOT a property of an object? a. g b. h c. m d. both g and h

d. both g and h