Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020PhysicsCenter of Mass, Momentum and CollisionPractice

The masses of five balls at rest and lying at equal distances in a straight line are in geometrical progression with ratio 2 and their coefficients of restitution are each 2 3 . If the first ball be started towards the second with velocity u , then the velocity communicated to 5 th ball is

Options

  1. A5 9 u
  2. B5 9 2 u
  3. C5 9 3 u
  4. D5 9 4 u

Correct answer

D. 5 9 4 u

Step-by-step solution

We know that velocity of 2nd ball after collision is given by v 2 = u 1 1 + e m 1 ( m 1 + m 2 ) + u 2 ( m 2 - m 1 e ) ( m 1 + m 2 ) In present problem u 2 = 0 , m 2 = 2 m 1 and , hence v 2 = u 1 + 2 3 m 1 ( m 1 + 2 m 1 ) = 5 9 u As four exactly similar type of collisions are taking place successively, hence velocity communicated to fifth ball v 5 = 5 9 4 u

Practice Center of Mass, Momentum and Collision on Quantrex Academy →

More from Center of Mass, Momentum and Collision

Two identical bodies A and B of equal masses have initial velocities v₁ = 4 i m/s and v₂ = 4 j m/s respectively. The body A has acceleration a₁ = 6 i + 6 j m/s ^2 while the acceler 2026The position of center of mass of three masses 2 kg, 3 kg and 15 kg placed with respect to mid point ( p ) of normal bisector, as shown in the figure is _______. 2026Two blocks of masses 2 kg and 1 kg respectively, are tied to the ends of a string which passes over a light frictionless pulley as shown in the figure below. The masses are held at 2026The position of an object having mass 0.1 kg as a function of time t is given as r = (10t^2 i + 5t^3 j ) m. At t = 1 s, which of the following statements are correct ? A. The linea 2026A body of mass 14 kg initially at rest explodes and breaks into three fragments of masses in the ratio 2: 2: 3 . The two pieces of equal masses fly off perpendicular to each other 2026In a perfectly inelastic collision, two spheres made of the same material with masses 15 kg and 25 kg, moving in opposite directions with speeds of 10 ~m / s and 30 ~m / s , respec 2026Given below are two statements : Statement I : For a mechanical system of many particles total kinetic energy is the sum of kinetic energies of all the particles. Statement II : Th 2026In a scattering experiment, a particle of mass 2 m collides with another particle of mass m , which is initially at rest. Assuming the collision to be perfectly elastic, the maximu 2025 Full Center of Mass, Momentum and Collision list All NTA Abhyas JEE Main PYQs