A. 2J
B. 10J
C. 22J
D. -2J
更新1:
Does this question mean that the 3N force pushs the object to tavel a distance of 2.67m?
mechanics
2007-08-26 1:02 am
A 5kg object is initially travelling at a velocity of 2m/s.It is pushed by a 3N force in the direction opposite to its motion for 2.67m. What is the kinetic energy of the object after the push?
A. 2J
B. 10J
C. 22J
D. -2J
A. 2J
B. 10J
C. 22J
D. -2J
回答 (1)
2007-08-26 3:13 am
✔ 最佳答案
yes~the question mean use 3N to push of 2.67m只要use conservsion of energy 便可以計到
Work done by 3N=loss in K.E
Work done=Fx S
=3x2.67
=8.01 J
inital K.E.=1/2Xmv2
=1/2x5x4
=10J
final K.E.= inital K.E - Work done by 3N
=10- 8.01
=1.99 J
THE answer is A
收錄日期: 2021-04-27 13:37:02
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