posted by physics on .
A rope of negligible mass passes over a puley of a negligible mass attached to the ceiling. One end of the rope is held by stdent A of mass 70 kg who is at rest on the floor. The opposite end of the rope is held by student B of mass 60 kg who is suspended at rest above the floor
calculate the magnitude of the force exerted on the floor by student A
I said 700 N and aparently this is wrong and I don\'t see why
If this question is asking for the normal force i got 100 n but i\'m not sure that is what it is asking for
The suspended student B's weight is balanced by a rope force Mb*g = 588 N. This becomes an upward force on Student A. A is held in equilibrium by ground force Fg (up), rope force (up) and his weight Mb*g (down).
Fg + 588 = Mb*g = 686 N
Fg = 686 - 588 = 98 N
If you are using 10 m/s^2 for g, you'd get 100 N for the answer. I used 9.8.