Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 5

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A particle of mass $M,$ starting from rest, undergoes uniform acceleration. If the speed acquired in time $T$ is $V,$ the power delivered to the particle is

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Important Questions on Work, Energy and Power

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 6

The potential energy of a system increases if work is done ?

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 7

The potential energy of a particle in a force field is

U = \frac{A}{r^{2}} - \frac{B}{r}

where

A

and

B

are positive constants and

r

is the distance of particle from the centre of the field. For stable equilibrium, the distance of the particle is

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 8

A car of mass

m

starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude

P_{0} .

The instantaneous velocity of this car is proportional to

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 9

A block of mass

10 kg,

moving in

x

direction with a constant speed of

10 m s^{- 1},

is subject to a retarding force

F = 0.1 x J m^{- 1}

during its travel from

x = 20 m

to

30 m

Its final

KE

will be : ?

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 10

Two similar springs

P

and

Q

having spring constants

K_{P}

and

K_{Q}

, such that

K_{P} > K_{Q}

. They are stretched, first by the same amount (case

a

), then by the same force (case

b

). The work done by the springs

W_{P}

and

W_{Q}

are related as, in case

(a)

and case

(b),

respectively

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 11

A particle of mass

m

is driven by a machine that delivers a constant power

k

watts. If the particle starts from rest, the force on the particle at time

t

is

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 12

A particle moves from a point

(- 2 \hat{i} + 5 \hat{j})

to

(4 j + 3 \hat{k})

when a force of

(4 \hat{i} + 3 \hat{j}) N

is applied. How much work has been done by the force?

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Alpha Question Bank for Medical: Physics>Chapter 8 - Work, Energy and Power>Exercise-3>Q 13

Consider a drop of rain water having mass

1 g

falling from a height of

1 k m .

It hits the ground with a speed of

50 m / s .

Takes

g

constant with a value of

10 m / s^{2}

. The work done by the

(i)

Gravitational force and the

(i i)

resistive force of air is