# 1000 kW of power is supplied to a motor. 90% of this is transmitted to a machine operating at 80% efficiency. The machine lifts an object of 10-tons with a velocity _____ m/s. (Assume g = 10m/s^2)

Category: Questions1000 kW of power is supplied to a motor. 90% of this is transmitted to a machine operating at 80% efficiency. The machine lifts an object of 10-tons with a velocity _____ m/s. (Assume g = 10m/s^2)
Editor"> Editor Staff asked 1 year ago

1000 kW of power is supplied to a motor. 90% of this is transmitted to a machine operating at 80% efficiency. The machine lifts an object of 10-tons with a velocity _____ m/s. (Assume g = 10m/s^2)

(a) 2

(b) 4

(c) 6

(d) 8

The question was asked in my homework.

This question is from Power in chapter Work, Energy and Power of Physics – Class 11
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Editor"> Editor Staff answered 1 year ago

Easiest explanation: Power transmitted to machine = (90/100) x (1000) kW

= 900 kW

Power used to lift object = (80/100) x 900 KW

= 720 kW

7,20,000 = F x v

= (1/2 x m x v^2) x v

= 10,000/2 x v^3

v^3 = 216

v = 6 m/s.