- Joined
- Jul 24, 2008
- Messages
- 26
- Reaction score
- 0
Hey guys, I have a specific question about tension that is really driving me crazy. It may be a little more than I need to know for the MCAT, but whatever. Anyway, here's the question:
A bucket weighing 3.2 kg is hanging from a massless rope. If the bucket is pulled upward by the rope with an acceleration of 1.6 m/s^2, calculate the tension in the rope. So I'm pretty sure there are 2 forces acting on the bucket: mg down, and Ft, tension of the rope, up. So the sum of the forces must = ma. So, Ft - mg = ma. Here's where I get messed up. Since the acceleration is up, don't g and a have to be opposite signs? If I make them opposite signs, i get something like 26.24. However, the answer in my book is 36, which you would get if a and g had the same sign. Can anyone explain why they have the same sign? Thanks so much
A bucket weighing 3.2 kg is hanging from a massless rope. If the bucket is pulled upward by the rope with an acceleration of 1.6 m/s^2, calculate the tension in the rope. So I'm pretty sure there are 2 forces acting on the bucket: mg down, and Ft, tension of the rope, up. So the sum of the forces must = ma. So, Ft - mg = ma. Here's where I get messed up. Since the acceleration is up, don't g and a have to be opposite signs? If I make them opposite signs, i get something like 26.24. However, the answer in my book is 36, which you would get if a and g had the same sign. Can anyone explain why they have the same sign? Thanks so much