# Forces in an M1 lift problemWatch

#1
In a lift problem, when calculating the tension in the cable when there is a man in the lift, do you consider the weight of the man as well as the lift or just the lift

so T - (weight of lift) = (mass of lift) x acc
or is it weight of lift+weight of man

Also do you take into account reaction forces and in which direction do these act??
0
8 years ago
#2
you must add the mass of the man ( or woman or bear ) to the mass of the lift... they comprise a single unit as far as the cable is concerned... the forces between the passenger & the floor are then internal forces which cancel out... they only need to be considered when the passenger is treated in isolation from the lift.

the bear

0
8 years ago
#3
I'd say its the weight of lift and the man, and you don't take into account reaction forces unless its like placed on a surface
0
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