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Work, Energy, and PowerClass 11thPhysics NCERT Exemplar Solutions Class 11th Chapter Sixphysics ncert solutions class 11thPhysics

A raindrop of mass 1.00 g falling from a height of 1 km hits the ground with a speed of 50 ms-1. Calculate

(a) The loss of P.E. of the drop. 

(b) The gain in K.E. of the drop. 

(c) Is the gain in K.E. equal to loss of P.E.? If not why. Take g = 10 ms-2

6 Views|Posted 8 months ago
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8 months ago

This is a short answer type question as classified in NCERT Exemplar

mass of the rain drop = 1g=1 * 10 - 3 k g

Height of falling h= 1km = 103m and g = 10m/s2 and sped of drop =50m/s

(a) Loss of PE of the drop =mgh= 1 * 10 - 3 * 10 * 10 3 = 10 J

(b) Gain in KE of the drop = 1/2mv2= ½ * 1 * 10 - 3 * 50 2 =1.250J

(c) No gain in KE is not equal to the loss in

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A bullet of mass m fired at 30° to the horizontal leaves the barrel of the gun with a velocity v. The bullet hits a soft target at a height h above the ground while it is moving downward and emerges out with half the kinetic energy it had before hitting the target. Which of the following statements are correct in respect of bullet after it emerges out of the target?

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(b) conserving energy between “O” ans ”A”

Ui + Ki = Uf + Kf

0+1/2mv2= mgh + 1/2mv’

( v ' ) 2 2 = v 2 2 = - g h

(v’)2=v2-2gh = v’= v 2 - 2 g h ……….1

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=1/2mv12=1/2[1/2mv’2]

1/2m(v1)2=1/4m(v’)2=1/4m[v2-2gh]

V1= v 2 2 - g h ………….2

From eqn 1 and 2

v ' v 1 = v 2 - 2 g h v 2 - 2 g h / 2 = 2

So v1 = v’/

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This is a multiple choice answer as classified in NCERT Exemplar

(c) m =150g =3/20kg

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Physics NCERT Exemplar Solutions Class 11th Chapter Six 2025

Physics NCERT Exemplar Solutions Class 11th Chapter Six 2025

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