MHB Mechanics- connected particles

[Shah 72]

A passenger lift had mass 500 kg. The breaking tension of the cable is 12000N. The max acceleration of the lift is 0.75 m/s^2
a) if the lift travels at its max acceleration, calculate the max mass of the passengers:
1)when the lift is accelerating upwards
2) when the lift is accelerating downwards
b) taking the average mass of a person to be 75 kg, what is the max number of passengers that should be allowed to travel in the lift?

 

[skeeter]

A passenger lift had mass 500 kg. The breaking tension of the cable is 12000N. The max acceleration of the lift is 0.75 m/s^2
a) if the lift travels at its max acceleration, calculate the max mass of the passengers:
1)when the lift is accelerating upwards
2) when the lift is accelerating downwards
b) taking the average mass of a person to be 75 kg, what is the max number of passengers that should be allowed to travel in the lift?

What have you accomplished with this one?

 

[Shah 72]

What have you accomplished with this one?

So it should be T- mass of lift× g- mass of passengers ×g= ( M+m) ×a
Iam not getting the right ans that is mentioned in the textbook

 

[Shah 72]

What have you accomplished with this
Thank you so much! I got the answers

 

[skeeter]

Are you going to share your solution so others may benefit?

That’s a big part of being a member of MHB. Get some help … give some help.

 

[Shah 72]

Are you going to share your solution so others may benefit?

That’s a big part of being a member of MHB. Get some help … give some help.

Ofcourse.
So I did T- Mg-mg=(M+m)×a
I got M=616kg
b) T- Mg-mg= -(M+m)×a
m=797 kg
2) I did 616/75= 8 people