Question

A lever of length 1m has been used to lift a load of 600N by applying an effort of 200N. If load is at 20cm from fulcrum, calculate mechanical advantages, velocity ratio and efficiency
solve numerical problem ​

Answer 1

Answer:

1) The Mechanical Advantage of the lever is 3

2) The velocity ratio of the lever is 4

3) The efficiency of the lever is 75%

Explanation:

A lever is a simple machine that is used to lift a heavy load with a little effort or force

The mechanical advantage is the ratio of the force output to the force input

The given parameters of the lever are;

The length of the lever = 1 m

The weight of the load (force output), $F_r$ = 600 N

The effort applied (force input), $F_e$ = 200 N

1) The Mechanical Advantage, MA of the lever is given as follows;

$MA = \dfrac{F_r}{F_e} = \dfrac{600 \ N}{200 \ N} = 3$

The Mechanical Advantage, MA of the lever = 3

2) The velocity ratio, V.R., is the ratio of the distance moved by the effort, $L_e$, to the distance moved by the load, $L_r$

For the lever, we have;

The distance of the load from the fulcrum, $L_r$ = 20 cm = 0.2 m

Therefore, we have;

The distance of the effort from the fulcrum, $L_e$ = 1 m - 0.2 m = 0.8 m

From which we have;

$V.R.= \dfrac{L_e}{L_r} = \dfrac{0.8 \ m}{0.2 \ m} = 4$

The velocity ratio of the lever = 4

3) The efficiency, η, is given as follow;

$\%Efficiency, \, \eta = \dfrac{M.A.}{V.R.} \times 100 = \dfrac{3}{4} \times 100 = 75\%$

The efficiency of the lever is 0.75 or 75%.