calculate maximum load

Question

6.3 A lift has a mass of 600 kg and is designed for a maximum upward acceleration of 3,2 m/s 2 . If the cross-sectional area of the cable is 3 cm 2 , and the maximum tension may not exceed 40 MPa, calculate the maximum load, in kilogram, that the lift may carry.

Answer 1

Find the the tension force.

F = Maximum tension * A

   = (40) (3* 10²)

  = 12000 N

Draw the free body diagram

Consider equilibrium equation.

F - mg = m_load a

12000 - (600)(9.81) =  (m_lift + m_load) (3.2)

m_load = (6114/3.2) - 600 = 1310.625 kg

Maximum load carry is 1310.625 kg