推 Morphee:這題有圖嗎? 10/28 14:33
推 Morphee:不過題幹已說明角度的意思了 10/28 15:28
推 xyz2k:θ角是指球從大砲口出來的角度 而α角是大砲砲口的角度 10/28 16:51
A cannon that is mounted at angle α to the horizontal on a
flatcar initially at rest. The mass of the car and cannon is
M. A cannonball of mass m is fired at speed V relative to the
cannon.
(a) Show that the recoil speed of the flatcar is (mV cosα)/(M+m).
(b) Show that the angle θ to the horizontal at which the ball
energes from the cannon is given by tanθ=(M+m)tanα/M.
(b)的部分我一直不是什麼意思耶...哪裡突然冒出來的θ呀？
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