HW33#5 – A block slides along a path that is without friction until the block reaches…

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

In the figure below, a block slides along a path that is without friction until the block reaches the section of length L = 0.90 m, which begins at height h = 2.0 m on a ramp of angle θ = 30°. In that section, the coefficient of kinetic friction is 0.46. The block passes through point A with a speed of 9.0 m/s. If the block can reach point B (where the friction ends), what is its speed there, and if it cannot, what is its greatest height above A?

這一題會有兩種可能,一種是在A點有足夠的Kinetic energy可以穿過B點,另外一種就是會停留在L線段的某處,不管哪一種做法,都先來判斷在A的Total energy是不是能夠比B點的Total energy還大,詳細解說請看影片