Power, Work, Efficicency

What is the efficiency of a machine if 55.3 J of work are done on the machine, but only 14.3 J is produced by the 1machine?

• 0.25 J
• 26%
• 386%
• 3.86 J

Tags

NGSS.HS-PS3-1

What is the work output of a machine that has a work input of 2,800 Joules and an efficiency of 92.3%? 

• 2,690J
• 92.3J
• 0.0082J
• 2,584.4

Tags

NGSS.HS-PS3-1

What is the unit of power?

• Watts (W)

• Joules (J)

• Newtons (N)

• Amps (A)

What is the power of a toaster which can transfer 10,000J of electrical energy in 10 seconds?

• 100,000W

• 100,000A

• 1,000W

• 1,000A

The rate at which electrical energy is converted into other forms of energy.

• Force
• Work
• Power
• Energy

The transfer of energy as electromagnetic waves.

• Radiation
• Efficiency
• Conduction
• Convection

A quantity that measures the ratio of work output to work input.

• Vector
• Speed
• Acceleration
• Efficiency

Which of the following is a unit of work?

• joule
• watt
• horsepower
• newton

Power is equal to work divided by

• time
• force
• distance
• mechanical advantage

An 80 kg skier stands at the top of a 40 meter slope. What is her gravitational potential energy before she skies down the slope?

• 3200 J

• 31,360 J

• 15,680 J

• 19.6 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

NGSS.HS-PS2-4