HW31#1 – A breadbox on a frictionless incline is connected, by a cord that runs over a pulley

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 1.9 kg breadbox on a frictionless incline of angle θ = 43° is connected, by a cord that runs over a pulley, to a light spring of spring constant k = 120 N/m, as shown in the figure below. The box is released from rest when the spring is unstretched. Assume that the pulley is massless and frictionless.

(a) What is the speed of the box when it moves 16 cm down the incline?

(b) How far down the incline from its point of release does the box slide before momentarily stopping?

(c) What are the magnitude and the direction of the box’s acceleration at the instant the box momentarily stops?