Answer :
(2) The work done is, 9.0 J
(3) The power of a machine measures its rate of doing work.
(4) The power used, 700 W
(5) A 750-W motor might also be rated as a 1-horsepower motor.
Solution for part (2) :
Formula used : \(W=F\times d\)
where,
W = work done = ?
F = applied force = 10 N
d = displacement = 0.9 m
Now put all the given values in the above formula, we get the work done.
\(W=(10N)\times (0.9m)}=9J\)
Therefore, the work done is, 9.0 J
Explanation for part (3) :
Power : it measures the rate of doing work by time.
Formula for power is, \(Power=\frac{Work}{time}\)
Solution for part (4) :
Formula used : \(P=\frac{W}{t}=\frac{F\times d}{t}\)
where,
W = work done
F = applied force = 700 N
d = displacement = 6 m
t = time taken = 6 s
Now put all the given values in the above formula, we get the work done.
\(P=\frac{700N\times 6m}{6s}=700W\)
Therefore, the power used, 700 W
Solution for part (5) :
As, 746 watt is equal to 1 horsepower
So, 750 watt is equal to \(\frac{750}{746}=1.005=1\text{ horsepower}\)
Therefore, a 750-W motor might also be rated as a 1-horsepower motor.
