Work, Power, Energy

Which does not illustrate kinetic energy?

• It is expressed in Joule.

• It depends upon the objects’ mass and speed.

• It is the energy an object possesses due to its motion.

• It depends upon the objects’ mass and objects’ height.

Tags

NGSS.MS-PS3-1

What is the potential energy of a 3kg ball that is on the ground?

• 0 J

• 3 J

• 9.8 J

• 29.4 J

A roller coaster whose average speed is 32 m/s is at the top of a 72m hill and weighs 966N. At the top of the hill the coaster car has ___________________ energy.

• only kinetic energy

• only potential energy

• mostly kinetic energy

• both kinetic and potential energy

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

A 100 N force is applied to move an object a horizontal distance of 5 meters at constant speed in 10 seconds. How much power is done?

• 50J

• 50W

• 500J

• 500W

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Which statement illustrates work done?

• A weightlifter holds a barbell above her head.

• A teacher applies a force to a wall and becomes exhausted.

• A rolling marble hits a note card and moves it across a table.

• A waiter carries a tray full of meals across a dining room at a constant speed.

Tags

NGSS.MS-PS3-5

A weightlifter holds a 100 kg barbell above her head. Is work done?

• Yes because there is a force applied to the barbell and the force causes a displacement of the barbell.

• Yes because there is an upward force applied to the barbell and the barbell moves vertically.

• No because no displacement occurred.

• No because there is no force applied.

Tags

NGSS.MS-PS2-2

What is the energy possessed by the cart?

• potential energy

• kinetic energy

• mostly potential

• mostly kinetic

Tags

NGSS.MS-PS3-2

NGSS.MS-PS3-5

What is the total mechanical energy of the object?

• 100J

• 75J

• 50J

• 25J

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Energy is

• how fast you do something.

• the ability to do work.

• confusing.

• how fast you lift something.

Tags

NGSS.MS-PS3-5

Jane carries a 5 kg box and Lorie carries a 10 kg box up a set of stairs, who did more work?

• Jane because his box was lighter.

• Lorie because her box weighed more.

• Can't tell.