work, power, and 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

NGSS.MS-PS3-5

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

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

• 0 J

• 3 J

• 9.8 J

• 29.4 J

Which statement does not illustrate power?

• A farmer plowing the rice field all day.

• A Siberian husky pulling a sled all day.

• A principal sitting on a chair while observing several classes all day.

• A teacher encoding his power point presentation in his laptop all day.

Tags

NGSS.MS-PS3-5

Who has the most power?

• Ms Criza who encodes her observation tools using 12000J of work in 20 minutes.

• Sir Pau who studies his 5 lessons for the next classes in 15 minutes.

• Mrs Punzalan who used 50N force to inoculate mushrooms at a speed of 2m/s.

• Mrs Masalunga who watches her learners while taking their quiz in 30 minutes.

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-PS3-5

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.

What is the energy possessed by the cart?

• potential energy

• kinetic energy

• mostly potential

• mostly kinetic

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-2

If the mass of the cart is 15kg, how much is the potential energy of the cart?

• 0J

• 1.2J

• 6J

• 58.8J

Tags

NGSS.MS-PS3-2