歡迎來到Yogi老師解題給你看,今天我要講解的是AP Physics C Mechanics的問題

(a) At a certain instant, a particle-like object is acted on by a force F with arrow = (3.7N)i hat(2.4 N)j + (9.3 N)k while the object’s velocity is v with arrow = −(2.0 m/s)i hat + (4.0 m/s)k. What is the instantaneous rate at which the force does work on the object?

(b) At some other time, the velocity consists of only a y component. If the force is unchanged and the instantaneous power is −12 W, what is the velocity of the object? (Express your answer in vector form.)

這個問題我們會利用到dot vector來解題,詳解請看影片