提示: 作者被禁止或刪除 內容自動屏蔽作者: avontube 時間: 2010-11-15 03:04 AM
Q1: if you consider only the x-direction movement, then the force provides 10 nt towards west (20 * 0.5 = 10). So, the acceleration is -1 m/s2. The distance of travel in 10 seconds is 10*10 - 0.5*100 = 50 m
Q2: assume the spring constant is k. After the spring is cut to 3/4 of its original length, the constant increase to be 4/3 of its original value. So, the answer will be (c).
Q3: if the string has no mass, and it is not moving, then the tension will be the same throughout the string. It is 20 - 4 = 16 nt