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A ball of mass 50 g moving at a speed of 2.0 m/s strikes a plane surface at an angle of incidence 45°. The ball is reflected by the plane at equal angle of reflection with the same speed. Calculate(a) the magnitude of the change in momentum of the ball(b) the change in the magnitude of the momentum of the ball. |
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Answer» THANKS for asking the question! ANSWER:: v = 2 cos 45° i - 2 sin 45° j v₁ = -2 cos 45° i - 2 sin 45° j (a) Change in momentum ⇒ m v = m v₁ ⇒0.05( 2 cos 45° i - 2 sin 45° j ) - 0.05 ( -2 cos 45° i - 2 sin 45° j ) ⇒0.1 cos 45° i - 0.1 sin 45° j + 0.1 cos 45° i + 0.1 sin 45° j ⇒0.2 cos 45° i Therefore , Magnitude = √[0.2/√2]² = 0.2 / √2 = 0.2 / 1.4 = 0.14 kg m/s (b) Change in magnitude of momentum of the ball = P(INITIAL) - P(final) = (2 x 0.5) - (2 x 0.5) = 0 Hope it helps! |
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