im not sure where to post this cos it includes mechanics formulae but im sure most of you have done mechanics as well since it is often included in maths programmes
a load of weight 7 kN is being raised from rest with constant acceleration by a cable. after the load has been raised 20 metres, the cable suddenly becomes slack. the load continues upwards for a distance of 4 metres before coming to instantaneous rest. Assuming no air resistance, find the tension in the cable before it became slack.
so obviously T = 7000 N + a(700), a being acceleration
but i can't seem to find this acceleration; ive tried using a velocity-time graph but there are too many unknowns for me; i am also a bit confused by what is meant by 'instantaneous' rest: does this mean constant velocity for 4 metres and then boom the graph line goes vertical?