Advantages of Simple Machines

Which is an example of someone using a simple machine to do work?

• a boy runs across a football field
• a banker counts money
• a mother pushes a stroller up a ramp into a building

• a girl eats a sandwich

We use simple machines to help increase the amount of ____ used, but NOT the amount of _____.

• work, force

• force, work

• force, energy

• energy, work

Simple machines make work easier by 

• increasing the energy needed to do the work, while reducing friction.
• changing the size or direction of the force, or both
• reducing work
• simple machines do all of these

What tool and unit is used to measure effort force like what is exerted on this pulley?

• spring scale; mililiters (mL)

• spring scale; Newtons (N)

• electronic balance;

  grams (g)

• electronic balance;

  Joules (J)

• ruler; centimeters (cm)

No machine can be 100% efficient because of

• Thermal energy

• Waste energy

• Convection energy

• Friction

How does a single fixed pulley make work easier?

• It changes the direction of the force.  

• It increases the size of the force.

• It increases the speed of the force

• It changes the friction across the load

Which pulley makes work easiest?

• 1
• 2
• 3
• they are all the same

How can we decrease the effort needed to make it easier to move a box up a ramp?

• Make the ramp shorter

• Add rubber to the bottom of the box.

• Make the ramp longer

• Pull it up instead of pushing it up.

What type of simple machine is found on the cap of a pickle jar?

• lever
• inclined plane
• screw
• wheel and axle

What is the point of using a wheel and axle?

• It does more work for more force

• It is shiny and decorative

• It does the same work, but takes less force

• It can be used on any terrain