QN A <eqn $m=&randnum(10,30,5);>kg crate is pulled by a horizontal
rope with a force of 
<eqn $F = &randnum(0.5, 2.0, 0.5) * $m> N 
along a rough floor with a constant velocify of 
<eqn &randnum(1.4, 2.2, 0.2);>m/s 
for a distance of 
<eqn $d = &randnum(8, 20, 2);>m.
How much work is done by the horizontal force?<_>J.

<eqn $W = $F * $d;>

QN A <eqn $m=&randnum(10,30,5);>kg crate is pulled at
constant speed across a rough floor by a rope at an angle of 
<eqn $theta = &randnum(20,60,5);> degrees above the
horizontal.  The tension in the rope is 
<eqn $mu_s = 0.2; 
    $rt = &rad($theta);
    $T = $mu_s * $m*9.8/(cos($rt) + $mu_s * sin($rt));
    $T = &threefigs($T);> N.
How much work is done if the box is pulled a distance
<eqn $d = &randnum(4,15,1);>m across the floor?<_>J

<eqn &fourfigs($T * cos($rt) * $d);>

QN A <eqn $m = &randnum(1,5,1);> kg block is sliding across a
horizontal surface with a speed of
<eqn $v0 = &randnum(0.5, 4.5, 0.5);> m/s.
What is the kinetic energy of the block?<_>J

<eqn $KE = 0.5 * $m * $v0 * $v0;>

QN Friction between the block and the surface brings the block to
rest in a distance of 
<eqn $mu_k = &randnum(0.1, 0.4, 0.05);
    $d = 0.5 * $v0 * $v0 / ($mu_k * 9.8);
    $d = &threefigs($d);> m.
How much work was done by friction on the block?<_>J

<eqn $W = -1.0 * $KE;>

QN What was the magnitude of the frictional force?<_>N

<eqn $F = abs($W/$d); &fourfigs($F);>

QN What was the coefficient of kinetic friction?<_>

<eqn $mu_k = $F/($m * 9.8); &threefigs($mu_k);>