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A rope of negligible mass passes over a pulley of negligible mass attached to the ceiling as shown above. One end of the rope is held by Student 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.

The first 2 questions asked for simple calculations, but now questions (d) and (e) ask:

(d) As Student B is accelerating at .25 m/s^2, is Student A pulled upward off the floor? Justify your answer.

Now I do not quite understand this..I guess it makes sense since the acceleration is so small, it doesn't have enough Fnet to make Student A go upwards. But (e) is as follows:

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

I do not understand how to calculate this. I have the answer as 1.6 m/s^2 as per my teacher's key. If anyone could explain how to arrive at this answer please help me out! I have completed FBDs for these two Students so it would be fine to speak to me in terms of the forces. Thanks to anyone who could help me with this!

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# Mechanics - Relative Tension

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