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A ball of mass m moving at a speed v makes a head-on collision with an identical ball at rest. The kinetic energy of the balls after the collision is three fourths of the original. Find the coefficient of restitution. |
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Answer» Thanks for asking the question! ANSWER:: Mass of FIRST ball = m Speed of first ball = v Mass of SECOND ball = m Let final velocities of first and second ball are v₁ and v₂ respectively. Using law of conservation of momentum, m(v₁ + v₂) = mv v₁ + v₂ = v Equation 1 And , v₁ - v₂ = ev Equation 2 Given:- Final KINETIC Energy = 3/4 Initial Kinetic Energy (1/2)mv₁² + (1/2)mv₂² = (3/4) x 1/2 mv² v₁² + v₂² = (3/4) v² [(v₁ + v₂)² + (v₁ - v₂)² ] / 2 = 3v² / 4 (1 + e²)v² / 2 = 3v² / 4 1 + e² = 3/2 e² = 1/2 e = 1 / √2 Hope it helps! |
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