3.4 | Work and Power

When you apply a force that displaces an object, you have:

• done work on that object.

• balanced the forces on the object.

• broken Newton's First Law of Motion.

• conserved the power used.

Tags

NGSS.HS-PS3-1

NGSS.HS-PS2-1

A 8.6 kg box is pushed across a floor 3.2 m with a force of 5.5 N. How much work is done on the box?

• 17.6 J

• 8.7 J

• 1.72 J

• No work is done.

A student carries a 10.5 kg book bag 15.3 m. How much work is done on the book bag by the student?

• No work is done.

• 160.65 J

• 1.46 J

• 25.8 J

An object of mass 6.8 kg is lifted to a height of 1.3 m. How much work is done on the object?

• 8.84 J

• 8.1 J

• 5.23 J

• No work is done.

If the direction an object is displaced is the same as the direction of a force applied to it:

• Positive work is done.

• Negative work is done.

• No work is done.

If the direction of an applied force is anti-parallel (opposite) to the direction an object is moving:

• Negative work is done.

• Positive work is done.

• No work is done.

If the direction an object is displaced is perpendicular to the direction of a force applied to it:

• No work is done.

• Positive work is done.

• Negative work is done.

How much power is required to do 40.2 J of work in 3.3 s?

• 12.18 W

• 132.66 W

• 43.5 W

• 0.08 W

In order to do 20.5 J of work in 0.46 s, how much power is required?

• 44.57 W

• 9.43 W

• 32.35 W

• 11.56 W

A force of 4.6 N moves a 2.7 kg box a distance of 3.3 m in 6.8 s. How much power is exerted?

• 2.23 W

• 6.03 W

• 17.4 W

• 278.7 W

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2