A tree trunk, of mass 250kg, is pulled up a slope by a chain attached to a tractor.
The chain is at an angle of 10 degrees to the slope. The slope itself is at 8 degrees to the horizontal.
The tree trunk initially accelerates at 0.2 ms-2. A friction force, of magnitude 2000N, acts on the tree trunk.
(a) Modelling the tree trunk as a particle, find the initial tension in the chain.
(b) Explain why the tension in the chain will probably decrease.
I have answered part (a) correctly by using Newton's 2nd law parallel to the slope (Tension = 2428 N) but I am struggling with part (b).
The answer at the back of the book states "The resistance force will increase and it will stop accelerating".
The questions I have are:
1. Why will the resistance force increase? (Maybe due to air resistance?)
2. Why, if it stops accelerating, will the tension in the chain decrease?
Any help would be gratefully appreciated!