Question

calcute the time taken by a crane with a 98kw motor to lift coal of mass 1ton from a mine of depth 1000m?​

Answer 1

Answer:

time = 100s

Explanation:

power = 98kW = 98000 W

m = 1 ton = 1000 kg

h = 1000m

g = 9.8 m/s^2

power = energy/time

∴ time = energy/power

energy = mgh

so, time = 1000*9.8*1000/98000

∴ time = 100s

hope it helps

mark brainliest

Answer 2

The time taken by a crane is 90.71 seconds.

Explanation:

Work done by the crane, W = 98 kW = 98000 W

Mass of coal, m = 1 ton = 907.18 kg

Depth of the mine, h = 1000 m

The work done by the crane per unit time is called its power. It is given by :

$P=\dfrac{W}{t}\\\\P=\dfrac{mgh}{t}\\\\t=\dfrac{mgh}{P}\\\\t=\dfrac{907.18\times 9.8\times 1000}{98000}$

t = 90.71 seconds

So, the time taken by a crane is 90.71 seconds. Hence, this is the required solution.

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