Question

In a first class lever, a load of 1500N is lifted by an effort of 500N. If the load distance and effort distance are 10cm and 40cm respectively. Calculate MA, VR and efficiency. (5)​

Answer 1

Answer:

In a first-class lever, a load of 1500N is lifted by an effort of 500N. If the load distance and effort distance are 10cm and 40cm respectively.

1. Mechanical advantage = $3$
2. Velocity ratio = $4$
3. Efficiency  = $75\%$

Explanation:

• For a simple machine, the mechanical advantage, velocity ratio, and efficiency of a machine can be expressed as,

        $\text{ { Mechanical\ advantage }(M . A)}=\frac{\text { Load }}{\text { Effort }} = \frac{L}{E}$    ...(1)

        $\text { Velocity ratio }(\text { V.R })=\frac{E_{d}}{L_{d}}$         ...(2)

        $\text { Efficiency}\ (\eta) = \frac{\text { M.A }}{\text { V.R } }$                  ...(3)

Where,

   L   -    Load

   E   -   Effort

   $L_d$  -   Load distance

   $E_d$  -   Effort distance

In the question, it is given that,

$L = 1500\ N$                                  $E = 500\ N$            

$L_d = 10\ cm=0.10\ m$                   $E_d =40\ cm = 0.40\ m$  

Substitute the above values into equation (1)

$\text M \cdot \text A=\frac{1500}{500}=3$

V.R  can be obtained by substituting the values of $E_d$ and $L_d$ into equation (2)

$\text V \cdot \text R =\frac{0.40}{0.1}=4$

Using equation (3), Efficiency is,

$\eta = \frac{3}{4} \times 100 = 75 \%$