Work Energy Theorem

When no friction or external applied forces are present, the total mechanical energy of a system will

• Increase

• Decrease

• Remain Constant

When positive work by an external force is done on a system, the energy of the system will ________.

• Increase

• Decrease

• Remain the same

Tags

NGSS.HS-PS3-1

When negative work (by friction or external forces) is done on a system, the total mechanical energy will ______.

• Increase

• Decrease

• Remain the same

Based on the story being told by the energy bar graphs, which situation is happening?

• An object is moving up a hill and slowing down

• An object is being dropped from a height and falling to the ground

• An object has elastic energy and is released across a frictionless surface

• An object is thrown into the air and falls back down

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Based on the story being told by the energy bar graphs, which situation is happening?

• An object is moving up a hill and slowing down

• An object is being dropped from a height and falling to the ground

• An object has elastic energy and is released across a flat frictionless surface

• An object is thrown into the air and falls back down

• An object has elastic energy and is released up a frictionless ramp

Tags

NGSS.HS-PS2-1

At point # 5 , what is the Total Mechanical Energy of the roller coaster cars?

• It's the same as the Gravitational Potential Energy at point #4

• It's the same as the Gravitational Potential Energy at point #2

• It's the same as the Gravitational Potential Energy at point #1

• It's the same as the Kinetic Energy at point #2

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

The skateboarder shown above has a potential energy of 2,800 J and kinetic energy of 0J at a height of 4 meters. How much total mechanical energy will she have after 2 seconds? Neglect friction and air resistance.

• 2000J

• 1600J

• 1400J

• 2800J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Which Equation matches:

"A moving object is stopped."

• PE = KE

• W = PEel

• PE −W = KE

• KE −W = 0

Tags

NGSS.HS-PS2-1

Which Equation matches:

"A moving object speeds up."

• KE + W = KE

• W = PEel

• PE −W = KE

• KE −W = 0

Tags

NGSS.HS-PS2-1

In order to do work on an object, the force you exert must be...

• The maximum amount of force you are able to exert.
• In the same direction as the object's motion.
• In a direction opposite to Earth's gravitational force.
• quick and deliberate.

Tags

NGSS.HS-PS2-1