Physics B Problems

<p>Hi. I'm practicing some physics B Free responses from previous years but don't really know where to begin. I have the answers already, I just need someone to explain how to do them. Thanks:</p>

<p>The block of mass M1 is on a rough horizontal table. The string that attaches it to the block of mass M2 passes over a frictionless pulley of negligible mass. The coefficient of kinetic friction µk between M1 and the table is less than the coefficient of static friction M1</p>

<p>(a) In terms of M1 and M2 determine the minimum value of µk that will prevent the blocks from moving?</p>

<p>The blocks are set in motion byy giving M2 a momentary push. In terms of M1,M2,µk and g determine each of the following..</p>

<p>(b)The magnitude of the acceleration of M1?</p>

<p>(c) The tension in the string?</p>

<p>Answers:
B) ms = M2 / M1</p>

<p>C) a = (M2g - mk M1g) / (M1 + M2)</p>

<p>D) T = M2g - M2g(M2 - µkM1)/(M1 + M2)</p>

<p>Three blocks of masses 1.0, 2.0, and 4.0 kilograms are connected by mass less strings, one of which passes over a frictionless pulley of negligible mass, as shown above. Calculate each of the following.
a. The acceleration of the 4 kilogram block
b. The tension in the string supporting the 4 kilogram block
c. The tension in the string connected to the l kilogram block</p>

<p>(Sorry but I cant seem to get the pic on here- basically on one side of the pulley is a 4kg mass, and on the other side is a 2kg mass that is connected by a string to a 1kg mass)</p>

<p>A) 1.4 m/s2</p>

<p>C) 33.6 N</p>

<p>D) 11.2 N</p>