I dont really know where to start with this question, any help is greatly appreciated.
An elastic spring can have extension l1 under tension force of T1. This spring is placed on the slope of a hill with an angle [alpha] to the horizontal such that one end of the spring is fixed at the foot of the hill and the other end can move freely along the slope. A body of mass m, starting from rest at the top of the hill, is moving down the hill (neglect friction forces).
Knowing that the body comes to full stop when the spring is compressed by 2l1, find:
(a) the distance travelled by the body;
(b) its speed at the moment of contact with the spring.