Unit 9 Machines Test Review

In which of the following situations do your arms do work on books?

• holding a heavy stack of books while standing
• carrying a heavy stack of books
• dropping a stack of books onto a table
• picking up a pile of books from the floor

How much work is done in holding a 15 N sack of potatoes while waiting in line at the grocery store for 3 minutes?

• 15 J
• 45 J
• 0 J
• 5 J

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

A flat sloping surface that connects lower and higher elevations. It makes raising objects easier.  

• wedge
• screw
• lever
• inclined plane 

An inclined plane wrapped around a rod forms this simple machine 

• lever
• pulley
• screw
• wedge 

An axe is an example of a

• pulley
• inclined plane
• screw
• wedge 

The transfer of energy that occurs when a force makes an object move is known as 

• effort
• potential 
• kinetic 
• work 

Which of the following does a simple machine do?

• allows the users to apply less force over a longer distance
• reduce the amount of force needed to do work
• change the direction of the applied force
• all of the above

ADV: During a pull-up, a 90 kg man raises himself by 80 cm. Calculate the work done in a single pull-up.

• 720 Joules

• 72,000 Joules

• 1,125 Joules

• 112,500 Joules

Work output can never be ________ than work input.

• work

• distance

• greater

• work output

• work input