Quick Questions

 

1.  What is the static friction coefficient (ms) steel?

A)         ~ 0.1

B)         ~ 0.5

C)        ~ 1

                   D)        None of the above

Answer

2.  Generally, Which is larger:  ms or mk?

Answer

3.  What would happen to the force of kinetic friction (mk) if the contact surface area were half of its original value?

         A)         It would be half as big as before

         B)         No change

         C)        It would be twice as big as before

         D)        It would be four times as big as before

Answer 

4.  If surface area doesn’t have an effect on the friction, why are race cars always switching to wider tires for more traction?

Answer

5.  You are trying to push a 20kg wood sled over a felt carpet (ms = 0.29).  If you are pushing at an angle 15o above parallel, how much force is needed to get the sled moving?

Answer

6.  You are now pulling a 20kg wood sled over a felt carpet (ms = 0.29).  If you are pulling at an angle 15o above parallel, how much force is needed to get the sled moving?

Answer

 

 

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