Law of conservation of energy:
From law of conservation of energy,
mghi + 0 = 0 + (1/2)mvi2
ghi = (1/2)vi2
vi = sqrt (2ghi) = sqrt[(2)(9.8)(1.5)] = 5.42 m/s
As shown in the figure (Figure 1) , a superball with mass m equal to 50 grams is dropped from a height of hi =1.5 m. It collides with a table, then bounces up to a height of hf = 1.0 m. The duration of the collision (the time during which the superball is in contact with the table) is tc = 15ms. In this problem, take the positive y direction to be upward, and use g = 9.8 m/s2 for the magnitude of the acceleration due to gravity. Neglect air resistance.
a. Find the y component of the momentum, pbefore,y, of the ball immediately before the collision.
b. Find the y component of the momentum of the ball immediately after the collision, that is, just as it is leaving the table.
c. Find Jy, the y component of the impulse imparted to the ball during the collision.
d. Find the y component of the time-averaged force Favg,y, in newtons, that the table exerts on the ball.
e. Find Kafter - Kbefore, the change in the kinetic energy of the ball during the collision, in joules.
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What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Elastic Collisions concept. You can view video lessons to learn Elastic Collisions. Or if you need more Elastic Collisions practice, you can also practice Elastic Collisions practice problems.
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