HW33#3 – A cookie jar is moving up a 20° incline. At a point 55 cm from the bottom of the incline

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 cookie jar is moving up a 20° incline. At a point 55 cm from the bottom of the incline (measured along the incline), the jar has a speed of 1.5 m/s. The coefficient of kinetic friction between jar and incline is 0.16.

(a) How much farther up the incline will the jar move?
(b) How fast will it be going when it has slid back to the bottom of the incline?
(c) Do the answers to (a) and (b) increase, decrease, or remain the same if we decrease the coefficient of kinetic friction (but do not change the given speed or location)?

 

KEY: 這一題要考慮到摩擦力也會產生能量,觀念仍然是所有的能量要守恆(Conservative)