Exam 4 Physics Numbers 11-15 2016-2017

1. 15. Which of the following is evidence that frictional forces are present in a system?

A. Interactions in the system cause an increase in temperature.

B. Interactions in the system produce sound.

C. Mechanical energy is not conserved.

D. all of the above

A. the sum of kinetic energy and gravitational potential energy.

B. the sum of kinetic energy and elastic potential energy.

C. the sum of kinetic energy and all relevant forms of potential energy.

D. the sum of all forms of energy.

A. gravitational potential energy is converted to kinetic energy.

B. kinetic energy is converted to gravitational potential energy.

C. kinetic energy is converted to elastic potential energy.

D. friction cannot be ignored.

A. A football flies through the air.

B. A feather falls from the sky.

C. A figure skater gliding on the ice.

D. A hockey player digs his skates into the ice.

A. Kinetic energy is always conserved.

B. Potential energy is always conserved.

C. Mechanical energy is always conserved.

D. Total energy is always conserved.