HW33#6 – The cable of the elevator cab snaps when the cab is at rest, where the cab bottom …

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

The cable of the 1600 kg elevator cab shown the figure snaps when the cab is at rest at the first floor, where the cab bottom is a distance d = 4.9 m above a spring of spring constant k = 0.18 MN/m. A safety device clamps the cab against guide rails so that a constant frictional force of 4.3 kN opposes the cab’s motion.

(a) Find the speed of the cab just before it hits the spring.
(b) Find the maximum distance x that the spring is compressed (the frictional force still acts during this compression).
(c) Find the distance that the cab will bounce back up the shaft.
(d) Using conservation of energy, find the approximate total distance that the cab will move before coming to rest.

KEY: 這一題依然用Energy Conservation的觀念,不過要小心friction所造成的能量應該要算在哪一邊