本题目来源于试卷: Newton’s law of motion，类别为 美国物理杯赛(Physics Bowl)
[单选题]
17.14: A block is suspended in the air at the el:i8 jw)j uyb*pnq4(2, mvys are p.y*nyf(b2 c+f9a)zu fu f5xd of a string held by a person. The person pulls on the string uniformly accelerating the block upward for a short time. During this time, which one of the following choices correctly identifies the Newx 5cy+uf(2f bfu9fa)z ton’s Third Law pair force to the force of the string on the block?
A. the gravitational force from the Earth on the block
B. the force from the string on the person
C. the force from the person on the string
D. the force from the block on the string
E. the force from the person on the block
参考答案: D
本题详细解析:
暂无
| 
