Given the masses of various atomic particles m P = 1 , 0072 u , m n = 1 , 0087 u , m e = 0 .000548 u , m v ¯ = 0 , m d = 2 .0141 u , where p = proton, n ≡ neutron, e ≡ electron, v ¯ ≡ antineutrino and d ¯ ≡ deuteron. Which of the following process is allowed by momentum and energy conservation :

n + n → deuterium atom (electron bound to the nucleus)

EASY

Earn 100

An artillery piece of mass $M_{1}$ fires a shell of mass $M_{2}$ horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is :

59.62% studentsanswered this correctly

Important Questions on Laws of Motion

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A bomb of mass

18 kg

at rest explodes into two pieces of masses

6 kg

and

12 kg .

The velocity of

12 kg

mass is

4 m / s .

The kinetic energy of the other mass is

HARD

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A man holding a rifle (mass of person and rifle together is

100 kg

) stands on a smooth surface and fires

10

shots horizontally in

5 \sec

. Each bullet has a mass

10 g

with a muzzle velocity of

800 m s^{- 1} .

The velocity which the rifle man attains after firing

10

shots will be

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A stationary body explodes into two parts of masses

M_{1}

and

M_{2}

. They move in opposite directions with velocities

v_{1}

and

v_{2}

. The ratio of their kinetic energies is

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A bullet of mass

0.1 kg

moving horizontally with speed

400 m s^{- 1}

hits a wooden block of mass

3.9 kg

kept on a horizontal rough surface. The bullet gets embedded into the block and moves

20 m

before coming to rest. The coefficient of friction between the block and the surface is _______.

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

Two particles which are initially at rest move towards each other under the action of their mutual attraction. If their speeds are

v

and

2 v

at any instant, then the speed of center of mass of the system is,

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A block moving horizontally on a smooth surface with a speed of

40 m s^{- 1}

splits into two parts with masses in the ratio of

1 : 2 .

If the smaller part moves at

60 m s^{- 1}

in the same direction, then the fractional change in kinetic energy is :

HARD

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

An object of mass

5 kg

is projected with a velocity

20 m s^{- 1}

at an angle

60 °

, to the horizontal. At the highest point of its path, the projectile explodes and breaks up into two fragments of masses

1 kg

and

4 kg .

The fragments separate horizontally after the explosion, which releases internal energy such that the

K E

of the system af the highest point is doubled. The separation between the two fragments when they reach the ground is

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A ball of mass $10 kg$ moving with a velocity $10 \sqrt{3} m s^{- 1}$ along the $x$ -axis, hits another ball of mass $20 kg$ which is at rest. After the collision, first ball comes to rest while the second ball disintegrates into two equal pieces. One piece starts moving along $y$ -axis with a speed of $10 m s^{- 1} .$ The second piece starts moving at an angle of $30 °$ with respect to the $x$ -axis. The velocity of the ball moving at $30 °$ with $x$ -axis is $x m s^{- 1} .$ The configuration of pieces after the collision is shown in the figure below. The value of $x$ to the nearest integer is

Question Image

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A block of mass m attached to a massless spring is performing oscillatory motion of amplitude 'A' on a frictionless horizontal plane. If half of the mass of the block breaks off when it is passing through its equilibrium point, the amplitude of oscillation for the remaining system become ƒA. The value of ƒ is:

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A block of mass $m = 1 kg$ slides with velocity $v = 6 m s^{- 1}$ on a frictionless horizontal surface and collides with a uniform vertical rod and sticks to it as shown. The rod is pivoted about $O$ and swings as a result of the collision making angle $θ$ before momentarily coming to rest. if the rod has mass $M = 2 kg,$ and length $ℓ = 1 m,$ the value of $θ$ is approximately $(take g = 10 m s^{- 2})$

Question Image

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A particle of mass

m

moving with velocity

v

collides with a stationary particle of mass

2 m

. After collision, they stick together and continue to move together with velocity

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A body of mass

(4 m)

is lying in

x

y

plane at rest. It suddenly explodes into three pieces. Two pieces, each of mass

(m)

move perpendicular to each other with equal speeds

(υ) .

The total kinetic energy generated due to explosion is:

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

The principle of conservation of linear momentum can be strictly applied during a collision between two particles provided the time of impact,

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

An object of mass

m_{1}

collides with another object of mass

m_{2}

, which is at rest. After the collision the objects move with equal speeds in opposite direction. The ratio of the masses

m_{2} : m_{1}

is :

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A bomb at rest explodes into

3

parts of same mass. The momentum of two parts is

- 3 p \hat{i}

and

2 p \hat{j}

respectively. The magnitude of momentum of the third part is

EASY

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A man of

60 kg

is running on the road and suddenly jumps into a stationary trolly car of mass

120 kg

. Then the trolly car starts moving with velocity

2 {m s}^{- 1}

. The velocity of the running man was _____

m s^{- 1}

, when he jumps into the car.

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A block moving horizontally on a smooth surface with a speed of

40 {m s}^{- 1}

splits into two equal parts. If one of the parts moves at

60 {m s}^{- 1}

in the same direction, then the fractional change in the kinetic energy will be

x : 4

where

x =

________.

MEDIUM

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

Given the masses of various atomic particles

m_{P} = 1, 0072 u

m_{n} = 1, 0087 u

m_{e} = 0 .000548 u

m_{\bar{v}} = 0

m_{d} = 2 .0141 u

, where

p =

proton,

n \equiv

neutron,

e \equiv

electron,

\bar{v} \equiv

antineutrino and

\bar{d} \equiv

deuteron. Which of the following process is allowed by momentum and energy conservation :

HARD

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A man (mass

= 50 k g

) and his son (mass

= 20 k g

) are standing on a frictionless surface facing each other. The man pushes his son so that he starts moving at a speed of

0.70 m s^{- 1}

with respect to the man. The speed of the man with respect to the surface is:

HARD

Physics>Mechanics>Laws of Motion>Law of Conservation of Linear Momentum

A particle of mass

m

is projected from the ground with an initial speed

u_{\circ}

at an angle

α

with the horizontal. At the highest point of its trajectory, it makes a completely inelastic collision with another identical particle, which was thrown vertically upward from the ground with the same initial speed

u_{\circ}

. The angle that the composite system makes with the horizontal immediately after the collision is

An artillery piece of mass M1 fires a shell of mass M2 horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is :

Important Questions on Laws of Motion

Learn and Prepare for any exam you want !

An artillery piece of mass $M_{1}$ fires a shell of mass $M_{2}$ horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is :