MEDIUM

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Identify the sentence in the present perfect tense.

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Important Questions on Work, Energy and Power

MEDIUM

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

Consider the following radioactive decays

I. ${}_{92}U {\overset{- α}{⟶}}_{90} Th$ and

II. $_{90} Th \overset{- α}{⟶} {}_{88}{Ra}$

In which case group of parent and daughter elements remains unchanged.

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

The stream of a river is flowing with a speed of

2 k m h^{- 1}

. A swimmer can swim at a speed of

4 km h^{- 1}

. The direction of the swimmer with respect to the flow of the river, to cross the river straight, is

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A force acts on a

2 kg

object so that its position is given as a function of time as

x = 3 t^{2} + 5 .

What is the work done by this force in first

5

seconds?

HARD

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

What would be the IUPAC name for the element with the atomic number

120

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A particle of mass

m

and charge

q

is placed at a rest in a uniform electric field

E

and then released. The kinetic energy

K

attained by the particle after moving a distance

y

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

The velocity of

2 kg

body is changed from

(4 \hat{i} + 3 \hat{j}) m s^{- 1}

6 m s^{- 1}

. The work done on the body is

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A car starts from rest and moves on a surface in which the coefficient of friction between the road and the tyres increases linearly with distance (x). The car moves with the maximum possible acceleration. The kinetic energy (E) of the car will depend on x as

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A block of mass

5 kg

is resting on a smooth surface. At what angle a force of

20 N

be acted on the body so that it will acquire a kinetic energy of

40 J

after moving

4 m

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

The velocity $(v) -$ time $(t)$ graph of a particle of mass $2 kg$ moving in a straight line is as shown in the figure. The work done by all the forces in $t = 0$ to $t = 2$ on the particle is

Question Image

MEDIUM

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

100 g

light bulb dropped from a tower reaches a velocity of

20 m s^{- 1}

after falling through

100 m

. The energy transferred to the air due to viscous force is

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

Displacement of an object of mass

2 k g

varies as

s = 3 t^{2} + 5 .

Find work done by man from

t = 0

t = 5 s e c .

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

The ratio of work done by the internal forces of a car in order to change its speed from 0 to

V and

V

2 V

is (Assume that the car moves on a horizontal road) -

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A 0.098 kg block slides down a frictionless track as shown. The vertical component of the velocity of block at

A

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A particle moves in a straight line with retardation proportional to its displacement. Its loss of KE for any displacement

x

is proportional to

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A small ball of mass

20 g m

is projected with initial velocity

5 m / s

from point

A

along the circular groove of rad

10 m .

Find its angular momentum about

O

when it reaches at point

B

as shown in the figure.

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A chain of length

l < \frac{π R}{2}

is placed on a smooth surface whose some part is horizontal and some part is quarter circular of radius r in the vertical plane as shown. Initially the whole part of chain lies in the circular part with one end at topmost point of circular surface. If the mass of chain is m, then work required to pull very slowly the whole chain on horizontal part is -

Question Image

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

The mass of a particle is

400

times that of an electron and the charge is double. The particle is accelerated by

5 V

. Initially, the particle remained in rest, then its final kinetic energy will be

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

A force of 5 N making an angle

θ

with the horizontal, acting on an object displaces it by 0.4 m along the horizontal direction. If the object gains kinetic energy of 1J, the horizontal component of the force is

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

An inclined track ends in a circular loop of the radius

r

. From what height on the track a particle should be released so that it completes the loop, assuming there is no friction?

Question Image

EASY

Physics>Mechanics>Work, Energy and Power>Work Energy Theorem

When work done on a particle is positive

Identify the sentence in the present perfect tense.

Important Questions on Work, Energy and Power

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