Energy, Work, Machines, and Power

Which energy transfer takes place when a wood log burns in a fire?

• Chemical to thermal energy

• Chemical to kinetic energy

• Electrical to heat energy

• Nuclear to heat energy

Tags

NGSS.HS-PS1-4

• A

• B

• C

• D

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-8

NGSS.HS-PS3-2

• 2.5 m/s

• 10 m/s

• 25 m/s

• 125 m/s

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

A trolley is pushed with a force that causes it to move a certain distance. It moves in the direction it is pushed.

Which represents the combination of force and distance that means the smallest amount of work is done on the trolley?

• Force = 20N

  Distance = 20N

• Force = 40N

  Distance = 10N

• Force = 50N

  Distance = 6.0N

• Force = 70N

  Distance = 4.0N

• 1/2 mv^2

• mgh + 1/2 mv^2

• mgh - 1/2 mv^2

• mgh

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

• 8.0/0.5 x 100%

• 7.5/0.5 x 100%

• 0.5/8.0 x 100%

• 7.5/8.0 x 100%

Tags

NGSS.HS-PS3-1

• A

• B

• C

• D

• Lifting the box from the ground to the high shelf slowly

• Lifting the box from the ground to the high shelf quickly

• Lifting the box from the ground to the low shelf slowly

• Lifting the box from the ground to the low shelf quickly

Tags

NGSS.HS-PS2-1

• Thermal -> kinetic and gravitational potential

• Gravitational -> kinetic + thermal

• Kinetic -> Gravitational potential + thermal

• Gravitational potential + kinetic

  -> thermal

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

• x

• y

• z

• x + z