1. A force diagram of both load and helicopter is shon below:
where,
fg1 is the weight of helicopter, fg2 the weight of the load, T1 = T2 is the tension on the cable and th is the force due to thrust up.
Based on the given information and in the previous scheme, you can conclude:
forces acting on the helicopter: 3
forces acting on the load: 2
The forces on the system are balanced because the speed of the motion of both load and helicopter is constant.
The tension in the cable is obtained by using the forces on the load.
The sum of the forces is zero becasue the forces are balanced, then:
T2 - fg2 = 0
T2 = fg2
now, consider that fg2 = m*g, where m is the mass of the load (500 kg) ang the gravitational acceleration constant (9.8 m/s^2). Then, by replacing, you obtain:
T2 = fg2 = m*g = (500kg)(9.8m/s^2) = 4900N
The tension in the cable is 4900N
The thrust the helicopter generates is calculate by consider the balance of the forces on the helicopter:
th - T1 - fg1 = 0
th = T1 + fg1
Now, consider that T1 = T2 = 4900N and fg1 is the weight of the helicopter:
fg2 = M*g = (4000kg)(9.8m/s^2) = 39200N
Then, by replacing fg2 and T2 you get for th:
th = 4900N + 39200N = 44100N
The thrust generated by the helicopter is 44100N
