physics ---urgent
2008-12-27 8:35 pm
Tom and John stand on two trolleys of neglible masses. both boys are initially at rest and Tom holds a ball of 3 kg. The masses of Tom and John are 30kg and 27 kg respectively. After Tom has thrown the ball to John, Tom moves backwards with a speed of 1m/s. What is the speed of John after he has caught the ball ?
回答 (1)
2008-12-27 10:03 pm
✔ 最佳答案
Assume backward is negative,forward is positive.mv+MV=0
30(-1)+3V=0
V=10m/s
mu+MU=(m+M)v
27(0)+3(10)=30(v)
v=1m/s
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