# Pulley system

1. Nov 17, 2008

### cflemer

1. The problem statement, all variables and given/known data
A rope of negligible mass passes over a pulley of negligible mass attached to the ceiling. One end of the rope is held by Student A of mass 70 kg, who is at rest above 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.

a. Calculate the magnitude of force exerted by the floor on Student a.

Student B now climbs up the rope at a constant acceleration of .25 m/s^2 with respect to the floor.
b. Calculate the tension in the rope while Student B is accelerating.

c. As Student B is acceleration, is Student A pulled upward off the floor? Justify your answer.

d. With what minimum acceleration must Student B climb up the rope to life Student A upward off the floor?

2. Relevant equations
Ma=70 kg
Mb= 60 kg

Attempt:
(a)F=ma
F=(130 kg) (9.81 m/s^2)
F= 1,275.3 N

d. No, Student B has a smaller mass than student A, thus they will not be able to lift A off the ground.

Last edited: Nov 17, 2008