A particle of mass m is initially at rest at the origin. It is subjected to a force and starts moving along the x - axis. Its kinetic energy changes with time as d K d t = γ t , where γ is a positive constant of appropriate dimensions. Which of the following statements is (are) true?

The distance of the particle from the origin increases linearly with time

Both kinetic energy and potential energy

EASY

Earn 100

The cause of increases in kinetic energy when a man starts running without his feet slipping on ground is asked from two students.

Ricky : Cause of increase in kinetic energy is work done by friction force without which he cannot run.
Anil : Cause of increase in kinetic energy is work done by internal forces of the body.

50% studentsanswered this correctly

Important Questions on Physics

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

A person of mass

100 kg

reaches a height in

10 seconds

. Find the power used by the person (

g = 10 \frac{m}{s^{2}}

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

Heat and work done by the heat was discovered by

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

1 kWh

equal to

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

Which of the following graphs shows correct relation of kinetic energy (E), potential Energy (U) and height (h) from the ground of a particle?

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

A rod of length

l

and mass

m

fixed at one end, is hanging vertically. The other end is now raised so that the rod makes an angle

30 °

with horizontal line. The work done in the process will be :

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

How fast should a man weighing

600 N

run to achieve a kinetic energy of

750 J

. Take

g = 10 m s^{- 2}

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

Which of the following graphs best represent the graphical relationship between Kinetic Energy

(K . E)

and momentum

(P)

of a body in motion?

HARD

Science and Mathematics>General Science>Physics>Work, Energy and Power

A particle of mass

m

is initially at rest at the origin. It is subjected to a force and starts moving along the x - axis. Its kinetic energy changes with time as

\frac{d K}{d t} = γ t,

where

γ

is a positive constant of appropriate dimensions. Which of the following statements is (are) true?

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

Flying birds has

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

The temperature of the water at the bottom of a water fall is higher than that of the water at the top, because :

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

Spring constant of a spring is

K = 6 \times 10^{3} N / m

. Work done to stretch it

10^{- 2} m

from mean position is

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

An object of mass

15 kg

is moving with uniform velocity of

4 m / s

. What is the kinetic energy possessed by the object?

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

A particle which is experiencing a force, given by

\vec{F} = 3 \hat{i} - 12 \hat{j}

, undergoes a displacement of

\vec{d} = 4 \hat{i}

. If the particle had a kinetic energy of

3 J

at the beginning of the displacement, what is its kinetic energy at the end of the displacement?

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

The work done to increase the velocity of a car from

30 km h^{- 1}

60 km h^{- 1}

, if the mass of the car is

1500 kg

, is:

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

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?

MEDIUM

Science and Mathematics>General Science>Physics>Work, Energy and Power

A body of mass

m

starts moving from rest along

x -

axis so that its velocity varies as

v = a \sqrt{s}

where

a

is a constant and

s

is the distance covered by the body. The total work done by all the forces acting on the body in the first

t

second after the start of the motion is

MEDIUM

Science and Mathematics>General Science>Physics>Work, Energy and Power

A block of mass

10 kg

, moving in

x

direction with a constant speed of

10 m s^{- 1}

, is subjected to a retarding force

F = [(0 .1) x] J m^{- 1}

during its travel from

x = 20 m

30 m

. Its final kinetic energy will be:

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

In a simple Pendulum the displacement is equal to amplitude. Then kinetic energy will be

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

A force of

40 N

acts on a body, and body moves through a distance of

2

metre at an angle of

45 °

in the direction of the force. The work done by the force is

EASY

Science and Mathematics>General Science>Physics>Work, Energy and Power

In any physical or chemical process, the total energy:

Important Questions on Physics

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