Grade 12 Physics

Power is defined as:

• the something that enables an object to do work

• how much force an object has

• the rate at which work is done

• energy due to the position of something

Kaylee and Jessica were moving boxes of quiz bowl questions. They each moved 10 boxes. Jessica moved the 10 boxes in 30 minutes, while Kaylee did it in 20 minutes. Assuming the boxes required the same amount of force to move, and they were all moved the same distance, which of the following is true:

• Kaylee did more work than Jessica, because she did it faster.

• Jessica did more work than Kaylee, because she worked longer.

• Kaylee had more power than Jessica but did not do more work.

• None of the above.

What unit do we use to measure power?

• Joule

• Watt

• Newton

• Kelvin

A small motor does 4000J of work in 20 seconds. What is the power of the motor in watts?

• 0.005 Watts

• 200 Watts

• 80,000 Watts

• None of the Above

A 55 kg person walks up a staircase, and a second 55 kg person runs up the staircase. Who develops more power and why?

• the person who runs up because he takes less time

• the person who walks up because he takes more time, using more energy

• same power for both because both cover the same distance with the same force

• not enough information to determine

If Joe lifts a 100N box 2m above the floor in 2s, what is the power output?

• 10W

• 50W

• 100W

• 300W

How much energy does an incandescent light bulb rated at 100 W use in one hour?

• 360 J

• 3600 J

• 36,000 J

• 360,000 J

What is the purpose of this safety sign?

• To make sure students wear a protective apron.

• To make sure students put on gloves.

• To make sure goggles are worn before starting.

• To make sure all directions are read before beginning.

Charlotte is working on a science lab. She is using the piece of equipment shown.

Which safety symbol is most likely to be included in Charlotte's lab instructions?

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Mason is working on a science lab. He is using the equipment shown.

Which safety symbol is most likely to be included in Mason's lab instructions?

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