Answer : The correct option is, (D) A machine does 400 joules of work in 5 seconds.
Explanation :
Power : It is defined a the rate of doing work per unit time.
Formula used :
where,
P = power
w = work done
t = time
Now we have to determine the rate of power for the following options.
(A) A machine does 200 joules of work in 10 seconds.
(B) A machine does 400 joules of work in 10 seconds.
(C) A machine does 200 joules of work in 5 seconds.
(D) A machine does 400 joules of work in 5 seconds.
From this we conclude that, a machine does 400 joules of work in 5 seconds has the highest rate of power.
Hence, the correct option is, (D)
Answer:
η = 58.8%
Explanation:
Work is defined as the force applied by the distance traveled by the body.
where:
W = work [J] (units of joules)
F = force = 294 [N]
d = distance = 5 [m]
Efficiency is defined as the energy required to perform an activity in relation to the energy actually added to perform some activity. This can be better understood by means of the following equation.