Work Power and Simple Machines

Which is doing work?

• pushing a wall

• holding a box

• picking up a pencil

• sitting in a chair

Which of the following is the best example of work being done? 

• doing homework

• lifting a box

• pushing a stationary box

• holding a box

A machine with a 5-N input force and a 25-N output force has a mechanical advantage of?

• 2

• 5

• 20

• 125

Tags

NGSS.MS-PS2-2

The mechanical advantage of a pulley system depends upon?

• The diameter of the pulley wheels

• The length of the rope

• The number of sections of rope

• The direction of the input force

Which is not considered a simple machine?

• The pump

• The wheel & axle

• The wedge

• The screw

• The pulley

Which is not a simple machine?

• Wedge

• screw

• lever

• fulcrum

The Mechanical Advantage (MA) of a simple machine makes work

• Easier

• Harder

• No difference to the work done

• None Of the above

You apply a force of 18 N on to the end of a lever to open a paint can lid. The resistance of the lid is 9 N. Calculate the MA.

You apply a force on a crowbar to open a stuck door. The effort length of the

crowbar is 26 cm long and the resistance length is 4 cm. Find the MA of the crowbar.

You are using a ramp to move a heavy box into a moving truck. If the length of the ramp is 4 m and the height into the truck is 1m, what is the mechanical advantage of the ramp?