a machine is driven by a 100 kg mass that Falls 8 metre in 4 second. it lifts a load of mass 500 kg vertically upward (i) what is the force in Newton exerted by falling mass (ii) what is the work done by 100 kg mass falling through 8m (iii)what is the power input of the machine if efficiency of machine is 75% (iv) what is the power output of the machine (v) what is the work done by the machine in 4 second
Answers
Answer:
Explanation:
Given a machine is driven by a 100 kg mass that Falls 8 metre in 4 second. it lifts a load of mass 500 kg vertically upward (i) what is the force in Newton exerted by falling mass (ii) what is the work done by 100 kg mass falling through 8 m (iii)what is the power input of the machine if efficiency of machine is 75% (iv) what is the power output of the machine (v) what is the work done by the machine in 4 second
First we need to calculate final speed of 100 kg stone falling from 8 m height,
V = √2 x g x h = √2 x 9.8 x 8 = √16 x 9.8
V = 12.52 m / s
Now force = m x g
So force = 100 x 9.8
1. Force = 980 N
2. On the gravitational field work is done by the object. When the object is falling in gravitational field object does not do any work.
3. Now power input = force x velocity = 980 x 12.52 = 12,269.6 W
4. So power output = 0.75 x 12,269.6 = 9,202.2 W
5. Work done by machine is 75% of input power x time
= 75 / 100 x 12,269.6 x 4
= 36,808.8 J