Physics · Elastic and inelastic collisions in one and two dimensions

A plastic ball falls from a height of 4.9 metre and rebounds several times from

A plastic ball falls from a height of 4.9 metre and rebounds several times from the floor. What is the coefficient of restitution during the impact with the floor if 1.3 seconds pass from the first impact to the second one?

  • A. 0.9
  • B. \( 0 . \)
  • C. 0 .7 \)
  • D. 0.8

Step-by-step solution

The time from first to second impact equals twice the time to reach maximum height after rebound. The time to fall from height h=4.9 m is t = sqrt(2h/g) = 1 s (using g=9.8 m/s^2). After impact, the ball's upward speed is e times the impact speed. The time to go up and down is 2e*t = 2e = 1.3 s, so e = 0.65. The closest option is 0.7.
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