Question

a machine rated as 150w changes the velocity of a 10kg mass from 4ms to 10ms in 4s the efficiency of the machine is nearly​

Answer 1

Answer:

Work done by the machine =

2

mv

2

−

2

mvρ

2

there,

m=10 kg,v

f

=10 m/s and v

i

=4 m/s

So, Δw=1/2[10×10

2

−10×(4)

2

]

=1/2×10×84=4205

Avg Power applied by machine =

time taken

Δw

=

4

420

=105 w

Efficiency =

Rated Power

Applied Power

=

150

105

=0.7=70%