Question

8. A lever of length 9 cm has its load arm 5 cm long
and the effort arm is 9 cm long. (a) To which class
does it belong ? (b) Draw a diagram of the lever showing
the position of the fulcrum F and directions of both
the load L and effort E. (c) What is the mechanical
advantage and velocity ratio if the efficiency is 100%?
(d) What will be the mechanical advantage and velocity
ratio if the efficiency becomes 50% ?​

Answer 1

Answer:

The mechanical advantage and the velocity ratio is 1.8 and 1.8

Explanation:

Given that,

length l = 9 cm

load arm = 5 cm

effort arm = 9 cm

efficiency = 100%

The mechanical advantage is defined as:

M.A =\dfrac{effort\ arm}{load\ arm}M.A=

load arm

effort arm

M.A=\dfrac{9}{5}M.A=

5

9

M.A=1.8M.A=1.8

The velocity ratio is

The efficiency is defined as:

\eta=\dfrac{M.A}{V.R}η=

V.R

M.A

V.R=\dfrac{M.A}{\eta}V.R=

η

M.A

V.R=\dfrac{1.8\times 100}{100}V.R=

100

1.8×100

V.R = 1.8V.R=1.8

Hence, The mechanical advantage and the velocity ratio is 1.8 and 1.8