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

A massive vertical wall is approaching a man at a speed u . When it is at a distance of 10   m , the man throws a ball with speed 10   m / s at an angle of 37 ° , which after having a completely elastic collision with the wall, reaches back directly into the hands of the man. The velocity of the wall is

Options

  1. A13 3 m/s
  2. B18 2 m/s
  3. C26 4 m/s
  4. D31 5 m/s

Correct answer

A. 13 3 m/s

Step-by-step solution

As the vertical motion remains unaffected ​ T = 2 u sin θ g ⇒ T = 2 × 10 × 3/5 10 T = 6 5 s     ...(1) from coefficient of restitutation along the line of collision e = relative velocity of separation after collision relative velocity of approach before collision 1 = v - u 8 + u v - 2u = 8 ...(2) by the time (t 1 ) ball collide with wall, distance travelled by man = 10 - ut 1 t 1 = 10 8 + u ...(3) by the time t 2 ball reach the hand of man t 2 = 10 - u 1 v ...(4) Since T = t

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