A block and tackle system has 5 pulleys. If an effort of 1000 N is needed in the downward direction to raise a load of 4500 N,

Calculate —

(a)The mechanical advantage,

(b)The velocity ratio and,

(c)The efficiency of the system.

A woman draws water from a well using a fixed pulley. The mass of the bucket and water together is 6 kg. The force applied by the women is 70 N. Calculate the mechanical advantage. (Take g = 10 m s^-2).

In a block and tackle system consisting of 3 pulleys, a load of 75 kgf is raised with an effort of 25 kgf.

Find —

(i) the mechanical advantage,

(ii) the velocity ratio, and

(iii) the efficiency.

A fixed pulley is driven by a 100 kg mass falling at a rate of 8.0 m in 4.0 s. It lifts a load of 75.0 kgf.

Calculate —

(a) The power input to the pulley taking the force of gravity on 1 kg as 10 N.

(b) the efficiency of the pulley, and

(c) the height to which the load is raised in 4.0 s.