Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main20203 Sep 2020Evening ShiftPhysicsCenter of Mass, Momentum and CollisionActual

A block of mass 1 . 9 kg is at rest at the edge of a table, of height 1 m. A bullet of mass 0 . 1 kg collides with the block and sticks to it. If the velocity of the bullet is 20 m s - 1 in the horizontal direction just before the collision then the kinetic energy just before the combined system strikes the floor, is [Take g = 10 m s - 2 . Assume there is no rotational motion and loss of energy after the collision is

Options

  1. A21   J
  2. B20   J
  3. C19   J
  4. D23   J

Correct answer

A. 21   J

Step-by-step solution

Conservation of linear momentum 0 . 1 × 20 = 0 . 1 + 1 . 9 × v v = 1   m   s - 1 Using work energy theorem W g = ∆ k 2 × g × 1 = k - 1 2 × 2 × 1 2 ∴       k = 21   J

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 JEE Main PYQs