EASY
JEE Advanced
IMPORTANT
Earn 100

A bomb, initially at rest, explodes into several pieces.

(a) Is linear momentum of the system conserved? 

(b) Is kinetic energy of the system conserved? Explain.

Important Questions on System of Particles and Centre of Mass

EASY
JEE Advanced
IMPORTANT

You are standing perfectly still and then you take a step forward. Before the step your momentum was zero, but afterward you have some momentum. Is the principle of conservation of momentum violated in this case?

EASY
JEE Advanced
IMPORTANT
Does the centre of mass of a rocket in free space accelerate? Explain. Can the speed of a rocket exceed the exhaust speed of the fuel? Explain.
EASY
JEE Advanced
IMPORTANT

Discuss the possibility of conservation of linear momentum of a block moving on a rough inclined plane if μ=tanθ.

Question Image

MEDIUM
JEE Advanced
IMPORTANT
A shell is fired from a cannon with a speed of 100 m/s at an angle 30° with the vertical (y -direction). At the highest point of its trajectory, the shell explodes into two fragments of masses in the ratio 1: 2. The lighter fragment moves vertically upwards with an initial speed of 200 m/s. What is the speed of the heavier fragment at the time of explosion?
EASY
JEE Advanced
IMPORTANT

A mud ball at rest explodes into three fragments of masses in the ratio 1: 2: 1. The two equal masses move with velocities 2i^+5j^-6k^ and -4i^+3j^+2k^. Find the velocity of the third mass.

Question Image

MEDIUM
JEE Advanced
IMPORTANT

(a) A rail road car of mass M is moving without friction on a straight horizontal track with a velocity u. A man of mass m lands on it normally from a helicopter. What will be the new velocity of the car?

(b) If now the man begins to run on it with speed vrel  with respect to car in a direction opposite to motion of the car, what will be the new velocity of the car?

 

MEDIUM
JEE Advanced
IMPORTANT
Two trolleys A and B are free to move on a level frictionless track, and are initially stationary. A man on trolley A throws a bag of mass 10 kg with a horizontal velocity of 4 m s-1 with respect to himself on to trolley B of mass 100 kg.The combined mass of trolley A (excluding bag) and the man is 140 kg. Find the ratio of velocities of trolleys A and B, just after the bag lands on trolley B.
MEDIUM
JEE Advanced
IMPORTANT

Two identical buggies 1 and 2 with one man in each move along parallel rails. When the buggies are opposite to each other, the men jump in a direction perpendicular to the direction of motion of buggies, so as to exchange their places. As a consequence, buggy 1 stops and buggy 2 keeps moving in the same direction with its final velocity v. Find the initial velocities v1 and v2 of buggies. Mass of each buggy (without man) equals M, mass of each man is m; ignore frictional effects anywhere and the buggies are constrained to move along the rails only. 

Question Image