Simple Machines Review

• Drawings B & C
• Drawings A & E
• Drawings E & F
• Drawings B & D

• Lifting the rock would be easier.
• Lifting the rock would take less force.
• Lifting the rock would be harder.
• Lifting the rock would take less work.

Your family members are always leaving a sliding screen door open.  Every time the door is left open, bugs get into the house.  What would be the BEST way to use the design process and simple machines to solve the problem?

• Put a lock on the door so family members will not use it.
• Use pulleys and weights to design a way for the door to close by itself.
• Buy new wheels for the bottom of the door so it closes more easily.
• Place a wedge made of wood at the bottom of the door so the door will stay open.

Which is an example of a wheel and axle being used?

• using a stapler
• cutting food with a knife
• turning on a water faucet
• hitting a pitched softball

• It is being used as a lever to pry the nail out of the wood.
• It is being used as a wedge to split the wood into two pieces. 
• It is being used as a pulley to pull the nail out of the wood. 
• It is being used as a wheel and axle to rotate the nail out of the wood. 

What is a simple machine?

• a machine that changes the direction of a force
• a machine that makes work harder to do
• a machine that requires many forces
• a machine with many moving parts

Will is cutting a piece of paper with a pair of scissors. He says scissors are levers. Beth says scissors cut, so they are wedges. Which BEST explains who is correct?

• Scissors are levers held together by a pin that acts as a fulcrum. 
• Scissors have sharp blades that work as wedges when cutting something. 
• Scissors are not levers because no load is being lifted. 
• Scissors are two simple machines working together.

• pick up the rock by using his arms as a lever and put it into a wheelbarrow to move it
• put a smaller rock under the stick, as a fulcrum, and push down on the 
  stick 
• put a smaller rock under the stick, as a fulcrum, and pull up on the stick
• kick the rock across the yard by using his body as a simple machine

Engineers and scientists use a design process to invent or improve machines. They also use a design process to improve ways of doing things. What is the first step in the design process?

• Keep notes and drawings of your design throughout the process.
• Make a graph to show how well your design worked.
• Identify a need or problem to be solved.
• Make a prototype of your design.

Which of the following is NOT a simple machine?

• a wheel and axle
• a lever
• a car
• a pulley