Question

A block and tackle is used to lift an automobile engine that weighs 1800 N. The person exerts a force of 300 N to lift the engine. How many ropes are supporting the engine? (Remember that AMA = force output/force input.)

Answer 1

6

Step-by-step explanation:

The mechanical advantage of a machine is defined as the ratio between the output force and the input force:

`MA=(F_o)/(F_i)`

In this problem, we have

`F_o = 1800 N` is the output force

`F_i=300 N` is the input force

So, the mechanical advantage is

`MA=(1800 N)/(300 N)=6`

Moreover, the mechanical advantage of a pulley system is also equal to the number of ropes supporting the load. In this case, the mechanical advantage is 6, therefore the pulley system must have 6 ropes.