Answer: B
Explanation:
Weight B requires a force equal to 5 Kg whereas A requires a
force equal to 10
Single pulley questions are relatively straightforward.
If the pulley is fixed, then the force required is equal to
the weight. If the pulley moves with the weight, then the
force is equal to half of the weight.
Another way of thinking about this is to divide the weight
by the number of sections of rope supporting it to obtain the force needed to
lift it.
In A there is only one section of rope supporting the
weight, so 10/1 = 10Kg required to lift the weight. In B there are two sections
of rope supporting the weight,
so, 10/2 = 5 Kg required to lift it.
