Mechanical Energy Conservation

Which of the following IS NOT a key ingredient in determining work?

• velocity

• force

• displacement

• cause

Which of the is the equation for calculating work?

• W = Fd

• W = ma

• W = mv

• W = mc²

Work is defined as applying a force on an object that displaces the object in the direction of the applied force. Which of the following IS NOT an an example of work being done on an object?

• A waiter walking with a tray of food that he is holding with his hand under the tray.

• A horse pulling a plow through a field.

• A shopper pushing a cart down the aisle of a grocery sture.

• A weightlifter lifting a barbell above his head.

Which of the following is an instance where a force hinders the displacement.

• A car skidding to a stop on a roadway surface.

• A student rolling a bowling ball down a bowling lane alley.

• A pitcher throwing a baseball.

• a man pushing a crate across a loading dock.

Tags

NGSS.HS-PS2-1

An instance where a force hinders a displacement is called __________________ work.

• negative

• false

• faux

• opposite

Negative work means that energy is being removed from the object.

• True

• False

An object is speeding up when: (Choose All That Apply)

• it is gaining kinetic energy.

• it is losing kinetic energy.

• it is gaining gravitational potential energy.

• it is losing gravitational potential energy.

Tags

NGSS.HS-PS3-2

The sum of the kinetic and potential energy in a system is known as the system's _____________________ energy.

• mechanical

• chemical

• thermal

• combined

Tags

NGSS.MS-PS3-4

How much kinetic energy (K) does a baseball with a mass of 0.143 kg have if it is travelling at a velocity of 41.1 m/s?

HINT: K = mv²/2

• 120.8 joules

• 89.7 joules

• 108.3 joules

• 156.6 joules

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

What is the maximum gravitational potential energy that this 1.3 kg ball can have in this situation?

HINT: U_g = mgh, where g = 9.8 m/s²

• 2.55 joules

• 1.65 joules

• 3.15 joules

• 3.94 joules