Conservation of Energy

Mechanical energy can be either potential or ________.

• Motion
• Kinetic
• Chemical
• Light

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-3

A pendulum is released from point C.  Which statement is correct as it  swings from C to A?

• The PE increases and KE decreases
• The KE increases and PE decreases.
• The PE is maximum at A.
• The KE is maximum at C and B.

Tags

NGSS.HS-PS3-2

A 40 kg crate is picked up by a crane to a height of 50m. The crate falls. What is the velocity of the crate just before it hits the ground?

• 2000 Joules
• 19,600 Joules
• 19,600 m/s
• 31.3 m/s

1. A ball has a 17 J of kinetic energy and its mechanical energy is 25 J. If the ball has a mass of 3.2 kg, what is its height above the ground?

• 0.26 m

• 0.52 m

• 5.2 m

• 25 m

Tags

NGSS.MS-PS2-4

NGSS.MS-PS3-2

NGSS.MS-PS3-5

What is mechanical energy?

• It is what metal creates when heated.
• All potential and kinetic energy in a system.
• It is motion of all matter.
• Energy of momentum.

Tags

NGSS.HS-PS3-2

Energy of motion is which type of energy?

• Potential
• Kinetic
• Sound
• Gravitational

Tags

NGSS.HS-PS3-2

An acorn falls from a tree. Compare its kinetic energy KE to its gravitational potential energy PE.

• KE increases and PE decreases

• KE decreases and PE decreases

• KE increases and PE increases

• KE decreases and PE increases

• cannot be determined

Tags

NGSS.MS-PS3-5

A mass is attached to one end of a string. The other end of the string is attached to a rigid support. The mass is released from rest at point A and swings in a vertical arc to points B, C, and D. Neglect air resistance.

At what point does the mass have the most potential energy (“energy stored gravitationally”)?

• A

• B

• C

• D

Tags

NGSS.MS-PS2-4

NGSS.MS-PS3-2

The law of conservation states that

• every action has an equal and opposite reaction
• all matter has thermal energy
• energy cannot be created or destroyed, only changes form
• heat moves from an object of higher temperature to an object of lower temperature

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

A ball is suspended by a lightweight string, as shown in the figure.   The ball is displaced to position 1 and released. The four labelled positions are evenly spaced along the arc of the ball's motion.  
Between which adjacent pairs is the gain in kinetic energy the greatest?

• 1 and 2
• 2 and 3
• 3 and 4
• They are all equal

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2