Work and Power

What is the equation for Work?

• W=1/2 (mv²)

• W=Fd

• W=1/2 (kx²)

• W=mgh

What is the equation for Kinetic Energy

• E_k=1/2 (mv²)

• E_k=Fd

• E_k=1/2 (kx²)

• E_k=mgh

A joule is a unit of

• power

• heat

• energy

• current

A 10 kg box is pulled a distance of 3m by a force of 30 N.

The work done is

• 9 J

• 30 J

• 90 J

• 900 J

Tags

NGSS.MS-PS2-2

A girl weighs 400 N. She runs up a flight of stairs of height 5 m in 4 seconds. Her power is:

• 320 W

• 400 W

• 500 W

• 2 000 W

Tags

NGSS.HS-PS3-2

Which of the following statements are true about work?

• Work is a form of energy.

• A Watt is the standard metric unit of work.

• Work is a time-based quantity; it is dependent upon how fast a force displaces an object.

• None of these.

Tags

NGSS.HS-PS3-2

Which of the following statements are true about power?

• If person A and person B do the same job but person B does it faster, then person A does more work but person B has more power.

• Powerful people or powerful machines are simply people or machines which always do a lot of work.

• Power refers to how fast work is done upon an object.

• None of these

Which of the following statements are true about kinetic energy?

• None of these

• Kinetic energy is the form of mechanical energy which depends upon the position of an object.

• If an object is at rest, then it does not have any kinetic energy.

• If an object is on the ground, then it does not have any kinetic energy.

Tags

NGSS.HS-PS3-2

Which of the following statements are true about potential energy?

• Both gravitational and elastic potential energy are dependent upon the speed of an object.

• Moving objects cannot have potential energy.

• None of these

• Potential energy is the energy stored in an object due to its position.

Tags

NGSS.HS-PS3-2