Review Questions

1.  Identify the simple machine described:

An inclined plane wrapped in a spiral around a post __________________________
Has a pivot point between the load and input force __________________________
A sloping flat surface used to raise objects. __________________________
An inclined plane with one or two sloping sides. __________________________
Can be fixed or moveable, consists of a rope wrapped around a wheel__________________________
A bar that is free to pivot around a fixed point. __________________________

2.  Give an example of each type of simple machine

Wheel and Axle  __________________________ Screw  __________________________
Inclined Plane __________________________ Lever __________________________
Pulley __________________________Wedge__________________________

3.  Identify the parts of this lever
A_____________________
B____________________
C _____________________

4.  What type of lever is pictured? ________________

5.  If you place a 100 N load at point A on the lever.  What force would be needed to balance it at point C.  No calculations necessary, use your “best guess”.
a.  100 N                 b. 200 N                  c.  50 N

6.  If B was perfectly centered, what force would balance a 100N load at point A? a.  100 N          b. 200 N               c.  50 N

7.  Draw a diagram of a class 2 lever and identify the fulcrum, load and effort.

Name a tool that acts as a class 2 lever: ____________________________

8.  Draw a diagram of a class 3 lever and identify the fulcrum, load and effort.

     Name a tool that acts as a class 3 lever: ____________________________

9.  Define WORK: _________________________________________________
What is the equation used to calculate work? _________________________
What unit is work measured in? _____________

10.  Define POWER: ________________________________________________
What is the equation used to calculate power? _________________________
pulleyWhat unit is work measured in? _____________

11.  Examine the two pulley designs…

Which one has the greatest MECHANICAL ADVANTAGE? _____

If 100 N of force are required in design A (F1), how much force would be necessary for design B (F2).  The distance of the rope in design B is double that of design A.   _________

Which design is a Block and Tackle? ______

Which one is a fixed pulley? _______

 

12.  What is MECHANICAL ADVANTAGE? How is it calculated?

 

What can increase the mechanical advantage of a wheel and axle? ____________________________
What can increase the mechanical advantage of an inclined plane? ____________________________
What can increase the mechanical advantage of lever? _________________________

13. You will also have problems to do for the test.  Here are two samples.

A)  How much work is done pushing a block 200 m with a force of 30 newtons?

 

B)  You push a stroller a distance of 10 meters, the amount of work expended is 2500 J.  What is the force used in pushing the stroller?

 

C)  A motor has a power of 300 W.  How much work can be done by this motor in 30 seconds?