Question

Unit 2 Newton's Laws ..
What is the acceleration a of an m = 11 kg pail of cement (or a rock) when pulled upward (not sideways!) on a rope by a person with a tensional force of F_T = 120 N?
(Hint: you need the pail's weight as well.)
The result that you get for the acceleration (about 0.1 to 0.9 m/s²) is more realistic than the one originally in the textbook. Note also that I included "by a person". Realistically though, neither a person nor a machine would try to actually accelerate a heavy object upward but would rather pull it up at constant speed.

Answer 1

There are two forces acting on the rock: mg is the gravitational force of the Earth, and F_T is the tension force acting upward. mg acts in the downward direction. The free-body diagram of the rock is shown below:

Net force accelerates the rock in the up direction

Using g=10m/s²