Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
A ball is dropped onto a horizontal surface from a height of 36 cm. After bouncing several times it comes to rest covering a total distance of 100 cm measured in a vertical direction. The percentage loss in its kinetic energy after its first impact is
(a) 36 (b) 64 (c) 53 (d) 96
A ball is dropped onto a horizontal surface from a height of 36 cm. After bouncing several times it comes to rest covering a total distance of 100 cm measured in a vertical direction. The percentage loss in its kinetic energy after its first impact is
(a) 36 (b) 64 (c) 53 (d) 96
Correct option (c) 53
Explanation:
One can write the series 100 = 36 + 2 x 36 (e2 + e4 + e6 + ..) giving e2 = 8/17 where e is the coefficient of restitution. Now, the percentage loss of kinetic energy = change in kinetic energy/original kinetic energy x 100. Note that the speed after impact is e times the initial speed. This gives the percentage loss as 52.94 which is almost 53 %.