Physics Power

An 80 N rope tension force is used to slowly pull a wagon 50 m up a hill. Calculate the work done by the rope if it pulls parallel to the hill

• -4000 J

• 4000 J

Tags

NGSS.MS-PS3-5

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

What type of energy is in this picture?

• Kinetic

• Potential

• Chemical

• Sound

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

A battery converts what type of energy to another?

• sound to kinetic

• light to heat

• mechanical to electrical

• chemical to electrical

Which equation is the one for power?

• P = F/A

• W = F x t

• p = m v

• P = W / t

On another day Bob does 30 000J of work riding up the slope and gaines 28 000J in E_p. If it takes the same amount of time 20 seconds to get to the top calculate the power he uses for both routes.

• 1400J and 1300J

• 1400J and 2000J

• 1400J and 1500J

• 14000J and 15000J

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-2

The roller coaster car has a mass of 500 kg. It is pulled from position 1 to 2 (30 m) by a motor. At the top of the ride the vertical distance top to bottom is 20 m. The motor pulls the car with a 4000 N force. Calculate the work done getting the car to the top of the ride.

• 100 000J

• 120 000J

• 800 000J

• 90 000J

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

Moving the car by the diagonal route uses 20 000J and lifting the car vertically uses 24 000J of energy. If both routes take the same time, (10 s) which route uses more power?

• Vertical one less energy is used per second

• Diagonal one as less energy is used per second

• Vertical one as more energy is used per second

• Diagonal one as more energy is used per second

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Bob (80 kg) uses 180 N of force to get him diagonally up the slope. The vertical distance is 2 m and the diagonal is 10 m. Calculate his gravitational potential energy at the top of the slope.

• 1600 J

• 160 J

• 3600 J

• 1800 J

Tags

NGSS.MS-PS2-4

Winnie and Eeyore have the same mass and have just finished climbing the same tree, but Eeyore was 4 seconds faster then Winnie. Who used the most power?

• Winnie as he took the longer time and did the same amount of work as Eeyore

• Winnie as he is shorter and could grip more as so did more work overall

• Eeyore as he did the same amount of work as Winnie but in a shorter time.

• Eeyore as he did more work than Winnie but in a shorter time

Tags

NGSS.MS-PS3-5