A motor is used to lift a load vertically upwards.The load has weight W.The motor produces useful power output P.The load is lifted at constant velocity v.Which expression gives the time taken for the motor to lift the load vertically upwards through adistance d ?A WdP B PWv C PWd D WPv
Question
A motor is used to lift a load vertically upwards.The load has weight W.The motor produces useful power output P.The load is lifted at constant velocity v.Which expression gives the time taken for the motor to lift the load vertically upwards through adistance d ?A WdP B PWv C PWd D WPv
Solution
The time taken for the motor to lift the load vertically upwards through a distance d can be found using the formula for power, which is work done per unit time.
The work done on an object is given by the force applied on it times the distance over which the force is applied. In this case, the force is the weight of the load (W), and the distance is d. So, the work done is Wd.
Power (P) is the work done per unit time (t). So, we can write the equation for power as P = Wd/t.
We want to find the time (t), so we rearrange the equation to solve for t: t = Wd/P.
So, the correct answer is A: Wd/P.
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