Question

3+4+3
5. (a) Define velocity ratio and mechanical advantage and how they are related to efficiency
of a machine. Find the condition for a reversible machine.
(b) In case of a lifting machine, efforts required to lift loads of 50 N and 80 N were 12 N and
18 N respectively. If velocity ratio for the machine was 6. determine:
(i) relation between the load and effort
(ii) the efficiency of the machine and the effort lost in friction at 50 N load
(iii) the maximum efficiency which can be expected from this machine.
(c)) An effort of 100 N is required to lift a load of 2500 N by the first system of pulleys
which has 5 movable pulleys. Determine (i) efficiency (ii) effort wasted in friction (iii) load
wasted in friction.​

Answer 1

Answer:

Mechanical advantage is defined as the ratio of resistance overcomes to the effort applied. Velocity ratio of simple machine is the ratio of distance travelled by effort to the distance travelled by load in the machine.

Answer 2

Answer:

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