- #1
goldfish9776
- 310
- 1
Homework Statement
I'm asked to find whether the object is moving or not
in this question , i was given the solution like this , i am wondering why the tension from 100kg to the roller(up) and the tension from point B to roller doesn't cancel each other?[/B]
Total force acting down the slope ignoring friction for the moment is
150 + 100*9.81*sin 20 - 784 = -299.3F_s = 0.2 *100 * 9.81 *cos(20) = 276.6N. Since the upward force is greater than this, the block is moving. Now we can use sliding friction in the sum of forces:
Total F = -299.3 + 0.2 x 100 x 9.81 x cos(20) = -299.3 + 184.4 = -114.9N. the minus sign says the sum of forces is upward, and the block slides up the ramp.