Work Done and Power

How do we calculate work?

• W = F * d

• w = f * D

• W = F * D

• w = f * d

The SI unit of work is?

• Joules

• Watts

• Newtons

• meters

Tags

NGSS.HS-PS2-1

The SI unit for power is...?

• Watts

• Joules

• Newtons

• Meters

Which of the following is the best example of work being done.

• doing homework

• lifting a box

• pushing a stationary box

• holding a box

True or false: when the distance an object moves is zero the work done on the object is also zero.  

• True

• False

You push against the back of your friends car that is stuck. You push and be become very tired, but the car does not move. Did you do work?

• Yes, work was done

• No, work wasn't done

What is the equation for power and energy?

• P = E/t

• E = P/t

• T = P x E

• P = W/t

Bob (80 kg) uses 180 N of force to get him up the slope. The vertical distance is 2 m and the diagonal is 10 m. Calculate the work he does.

• 1600 J

• 160 J

• 3600 J

• 1800 J

Tags

NGSS.HS-PS2-1

What is the difference between calculating power and work?

• Power takes into account the time it takes to complete a task

• Work takes into account the time it takes to complete a task

• Power is force/area

• Work is force/area

Which situation is work not done?

• lifting a 20 pound box off the floor

• holding a 20 pound box above the floor

• sliding a 20 pound box across the floor

• sliding a 20 pound box up an inclined plane