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A 0.440-kg blue bead slides on a frictionless, curved wire, starting from rest a

ID: 2077004 • Letter: A

Question

A 0.440-kg blue bead slides on a frictionless, curved wire, starting from rest at point A in the figure below, where h = 1.50 m. At point B, the bead collides elastically with a 0.690-kg green bead at rest. Find the maximum height the green bead rises as it moves up the wire. m Two blocks of masses m_1 = 1.80 kg and m_2 = 3.60 kg are each released from rest at a height of h = 5.40 m on a frictionless track, as shown in the figure below, and undergo an elastic head-on collision. (Let the positive direction point to the right. Indicate the direction with the sign of your answer.)

Explanation / Answer

velocity of the blue bead when it srtikes the green bead

v = sqrt(2gh) = sqrt(2*9.8*1.5) = 5.42 m/s

by the conservation of momentum we have

0.44* 5.42 + 0 = 0.44*v1 + 0.69v2

0.44v1 + 0.69v2 = 2.38 --------(1)

v2 - v1 = 5.42

0.44v2 - 0.44v1 = 2.38 ---------(2)

adding (1) and (2) we have

1.13 v2 = 4.76

v2 = 4.21 m/s

height recahed by green bead = v2^2 / 2g

= 4.21^2 / 2*9.8 = 0.9 m