Question

How long will it take a 2190 W motor to lift a 1.47 x 104 g box, 6.34 x 104 mm vertically.​

Answer 1

Answer:

4.2s

Explanation:

Given parameters:

Power = 2190W

Mass of box = 1.47 x 10⁴g

distance  = 6.34 x 10⁴mm

Unknown:

Time  = ?

Solution:

Power is the rate at which work is done;

 Mathematically;

        Power  = $\frac{work done}{time}$  

   Time  = $\frac{work done}{power}$  

 Work done  = weight x height

 convert mass to kg;

     100g = 1kg;

           1.47 x 10⁴g  = 14.7kg

convert the height to m;

          1000mm = 1m

          6.34 x 10⁴mm gives 63.4m

  Work done  = 14.7 x 9.8 x 63.4 = 9133.4J

  Time taken = $\frac{9133.4}{2190}$   = 4.2s