Work and Simple Machines

A student pulls a lever down 4 m. The lever lifts a box that weighs 20 N up a distance of 2 m. How much work was done on the box?

• 10 J

• 40 J

• 80 J

• 160 J

Charlie lifts a box with a force of 500 N and sets it on a table top 1.2 m above its starting position. Lauren pushes an identical box up a 5 m ramp from the floor to the top of the same table. Which person did more work?

• Charlie did more work.

• Lauren did more work.

• Both Charlie and Lauren did the same amount of work.

• The size of each individual must be known to determine who did more work.

If a large force is exerted on an object, when is no work performed?

• when the object moves

• when the object does not move

• when the power is too large

• when there is no friction

A baker pushes a cart full of rolls with a force of 20.0 N for a distance of 4.0 m. How much work does the baker do on the cart?

• .20 J

• 5 J

• 16 J

• 80 J

How much work does Juanita do if she uses a force of 40 newtons to pull 2 friends on a wagon for 32 meters?

• 1.25 J

• 640 N

• 1280 J

• 1280 N

Tags

NGSS.MS-PS3-5

Darla pushed a cart with 50 newtons of force 100 meters away from her house. How much work, measured in joules (J), did she do to move the cart?

• 2 J

• 50 J

• 150 J

• 5000 J

What is the mechanical advantage of a pulley system with 4 pulleys?

• 2

• 3

• 4

• 5

A lever is used to remove a rock from the ground. Which lever shown below has the greatest mechanical advantage?

• A lever with a lot of thickness and a medium length

• A lever with not a lot of thickness and a long length

• A lever with not a lot of thickness and a medium length

• A lever with a lot of thickness and a short length

Tags

NGSS.MS-ETS1-2

A construction crew must use a lever to lift a boulder. The mechanical advantage of the lever is 6 and the lever applies a force of 1600 N to the rock. What is the force that the construction crew must apply to the lever?

• 134 N

• 267 N

• 380 N

• 534 N

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Luisa used a claw hammer to remove nails from a piece of wood she wants to paint. What is the effort distance for a claw hammer if the resistance distance is 6.0 cm and the mechanical advantage is 6.0?

• 24

• 27

• 30

• 36