A block weighing 21 N is held at rest against a vertical wall by a

horizontal force

of magnitude 59 N. The coefficient of static

friction between the wall and the block is 0.56, and the coefficient of

kinetic friction between them is 0.37. A second

force

is applied to the block and directed parallel to

the wall with this magnitude and direction: 62 N, up. What is the

frictional force on the block, including sign? Take the direction up the

wall as positive, and down the wall as negative. Next, calculate the

acceleration, including sign, of the block.