B. Newton’s Laws Quantitative Exam

300 Points (50 points each)

 

1.       A load of steel of mass 6000 kg rests on the flatbed of a truck.  It is held in place by metal brackets that can exert a maximum horizontal force of 8000 N.  When the truck is traveling 20 m/s, what is the  minimum stopping distance if the load is not to slide forward into the cab?

 

2.       A bulldozer drags a log weighing 500 N along a rough surface.  The cable attached to the log makes an angle of 30ø with the ground.  The coefficient of static friction between the log and the ground is 0.50.  What minimum tension is required in the cable in order for the log to begin to move?

 

 

3.       Consider the Atwood machine in the above figure.  m1=33.0 kg and  m2=11.0 kg and the pulley mass is negligible.

a) Determine the acceleration.

b) What is the tension in the connecting string?

 

 

 

4.       A 42.0kg block of ice slides down the plane incline 34.0o in the figure.  Assuming friction is negligible, what is the acceleration of the block down the incline?

          a.   5.48 m/s2

          b.   8.12 m/s2

          c.   9.80 m/s2

          d.   6.61 m/s2

 

5.       Consider the 42.0kg block of ice illustrated in the previous problem.  Assuming the kinetic coefficient of friction is 0.060, what is the acceleration of the block down the incline?

          a.   5.48 m/s2

          b.   3.72 m/s2

          c.   4.73 m/s2

          d.   4.99 m/s2

 

 

6.  Refer to the following diagram in your textbook for this problem  (See figure 4.37 on p. 134 of your textbook):  Assume that m1 = 0.25 kg, m2 = 0.50 kg and m3 = 0.75 kg.  Assuming ideal conditions for the pulleys and string, what would be the minimum ms between m3 and the table so that the system would stay at rest (eg.  to keep the blocks from moving)

                                      a.  0.90

                                      b.  0.33

                                      c.  0.58

                                    d.  1.00