physics
posted by mera on .
Your engineering firm is asked to specify the maximum load for the elevators in a new building. Each elevator has mass 500 kg when empty and maximum acceleration 2.25 m/s^2. The elevator cables can withstand a maximum tension of 19.6 kN before breaking. For safety, you need to ensure that the tension never exceeds twothirds of that value. What do you specify for the maximum load?How many 75.0\rm kg people is that?

Maximum elevator load = M*g, where M is the mass of passengers and/or freight.
Require that
(500 + M)*(g + a) = 1.5 * Tmax
(500 + M)*12.05 = 29.4*10^3 N
Solve for M.
M = 2440 kg
Divide M by 75 kg for the maximum number of people.