1. The problem statement, all variables and given/known data A Lift in a mine shaft takes exactly one minute to descend 500m. It starts from rest , accelerates uniformly for 12.5 seconds to a constant speed which it maintains for some time and then decelerates uniformly to stop at the bottom of the shaft. The mass of the lift is 5 tonnes and on the day in question it is carrying 12 miners whose average mass is 80 kg. (i) Sketch the speed-time graph of the lift. During the first stage of the motion the tension in the cable is 53 640 N (ii) Find the acceleration of the lift during this stage. (iii) Find the length of time for which the lift is travelling at constant speed and the final deceleration. 2. Relevant equations mg-T=ma Positive down g=9.8m/s^2 3. The attempt at a solution (i) Don't know how to get a graph up so i'll just describe it; a linear increase in speed from rest for 12.5s. Then a horizontal line representing a constant speed from some time. After that, a deceleration at an unknown time producing a linear decrease in speed to rest, at 60s. (ii) (5000+80*12)g - T = (5000+80*12)a a=0.8m/s^2 (iii) This is the part I can't do. I don't know where to start without any information on the time or distance at the start of deceleration. The answer I get from the back of the book is 40s and 1.33m/s^2.