Physics Work Energy Power

The space shuttle (RIP) used to be transported to its launch pad by a large mobile platform. If the platform holds up the space shuttle 4.5x10⁶kg while rolling 800m to the launch pad, how much work does it do in holding up the shuttle?

• More than 0 but less than 1x10⁵ J

• More than 1x10⁵J but less than 1x10⁷J

• More than 1x10⁷ J but less than 1x10⁹ J

• More than 1x10⁹ J

• 0 J

How are work and energy related?

• The work done by an external force acting on an object causes a change in the mechanical energy of the object.

• Work is the same thing as energy. They are equal.

• Energy is mgh, and work is mv²/2

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NGSS.HS-PS3-3

If you pull the trolley along a flat floor horizontally. Which force do you use to calculate the work done.

• Weight

• Pulling force

• Normal forrce

• Friction

Tags

NGSS.HS-PS2-1

Bob (80 kg) uses 180 N of force to get him up the slope. The vertical distance is 2 m and the diagonal is 10 m. Calculate the work he does.

• 1600 J

• 160 J

• 3600 J

• 1800 J

Tags

NGSS.HS-PS2-1

If the net work done on an object is negative, then the object’s kinetic energy...

• decreases

• remains the same

• increases

• is zero

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NGSS.HS-PS3-1

NGSS.HS-PS3-2

On a force versus change in position graph, the area under the curve is a representation of...

• power

• KE

• PE

• work

How far does a car that pulled with a 5,000 N force go if 18,000 J of work is done on it?

• 3.8 m

• 3.7 m

• 3.2 m

• 3.6 m

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Bowling Ball A is dropped from a point halfway up a cliff. A second identical bowling ball, B, is dropped simultaneously from the top of the cliff. Comparing the bowling balls at the instant they reach the ground, which of the following are correct? Neglect air resistance.

• Ball A has half the kinetic energy and takes half the time to hit the ground as Ball B.

• Ball A has half the kinetic energy and takes one-fourth the time to hit the ground as Ball B.

• Ball A has half the final velocity and takes half the time to hit the ground as Ball B.

• Ball A has one-fourth the final velocity and takes one-fourth the time to hit the ground as Ball B.

• None of these are correct.

Tags

NGSS.HS-PS2-1

NGSS.HS-PS3-1

A net force (Fcosθ) acts on an object moving in the

positive x-direction along the axis over a distance of 4

meters, depicted in the graph at right. Find the work done by the force in the interval from 0.0 to 2.0 m.

• 0 J

• 3 J

• 3/cosθ J

• 6 J

A child pushes horizontally on a box of mass m which moves with constant speed v across a horizontal floor.

The coefficient of friction between the box and the floor is μ. At what rate does the child do work on the box?

• μmgv

• mgv

• μmg/v

• mgv/μ

Tags

NGSS.HS-PS3-2