Q.1
What effect do external forces like an applied force, friction force, or drag force have?
  • They have no effect on a system's mechanical energy.
  • They convert kinetic energy into potential energy.
  • They convert potential energy into kinetic energy.
  • They convert between mechanical energy and other forms of energy to change the total mechanical energy of the system.
Q.2
A 40-kg person is climbing 3 m up a flight of stairs in 6 seconds. How much work did they do climbing the stairs?
  • 400 J
  • 1200 J
  • 200 J
  • 120 J
Q.3
How high up is a 3200-kg plane if it hasJ of potential energy?
  • 10 m
  • 30 m
  • 307200000 m
  • 300 m
Q.4
What effect do external forces like an applied force, friction force, or drag force have?
  • They have no effect on a system's mechanical energy.
  • They convert kinetic energy into potential energy.
  • They convert potential energy into kinetic energy.
  • They convert between mechanical energy and other forms of energy to change the total mechanical energy of the system.
Q.5
If a 1300-kg car has been lifted so it hasJ of potential energy, it was lifted up ---.
  • 1.5 m
  • 150 m
  • 15 m
  • 0.67 m
Q.6
How does conservation of energy explain why something that is falling should speed up?
  • It gains kinetic energy because it gains potential energy.
  • It loses kinetic energy because no work was done on it.
  • It gains kinetic energy because it loses potential energy.
  • It loses kinetic energy because the Earth gains potential energy.
Q.7
A roller coaster whose average speed ism/s is at the top of ahill and weighs 966N. At the top of the hill the coaster car has ___________________ energy.
  • almost all kinetic energy
  • almost all potential energy
  • mostly kinetic energy
  • some kinetic and some potential energy
0 h : 0 m : 1 s