Work, energy

SI Unit of Energy

• Newton

• watts

• Joules

• meter

Calculate the PE of a 2 kg cat perched 10 meters above the ground.

• 20J

• 200J

• 2.04J

• 200W

When my velocity doubles, my kinetic energy increases by ______ times.

• 4

• 3

• 1.5

• 4.5

Calculate the Kinetic Energy (KE) of a girl whose mass is 50 kg who is moving at 4 m/s.

• 200 J

• 800 J

• 400 J

• 100 J

Bernie dives from a the top of a flagpole into a swimming pool below. His potential energy at the top is 10,00J. What is his kinetic energy when his potential energy reduces to 9.0J?

• 9990.3J

• 991.0J

• 1009.7J

• 10009.7J

How much work is done on a vacuum cleaner pulled 3 m by a force of 50 N at an angle of 30-degrees above the horizontal?

• 50J

• 80J

• 130J

• 150J

If 68 Joules were necessary to move a 4 Newton crate, how far was the crate moved?

• 272 m

• 17 m

• 4.05 m

• 272 cm

Gravitational potential energy depends on the ________ and ________ of the object.

• Height and mass

• Friction and movement

• Mass and Movement

• Height and Friction

Why does the total amount of mechanical energy stay constant in a system?

• energy is not created or destroyed

• energy leaves

• energy enters

• total energy =0

Work done by the sun in moving Earth in an orbit around it is an example of

• positive work

• negative work

• zero work

• none of the above