work output and input?

Question

How is the work output of a machine related to its work input?
a)always less
b) always greater
c) always equal
d) always zero



The mechanical advantage of a pulley system depends on
a) the diameter of the pulley wheels
b) the length of the rope
c) the number of sections of rope
d) the direction of the input force

Answer 1

a) In reality, the work output is always less in a machine because of friction. In a perfect world, the work would remain the same.

c) The mechanical advantage of a block and tackle (pulley system) depends on the number of sections of rope (also being the number of pulleys in the system.

Answer 2

1. Always less

2. The number of sections of rope.

HTH ☺


Doug