A 4.0-kg block slides down a frictionless incline making an angle of 50.0° with the horizontal.
(a) What is the total work done on the block when the block slides 1.0 m (measured along the incline)?
(b) What is the speed of the block after it has slid 1.2 m if it starts from rest?
(c) What is its speed after 1.2 m if it starts with an initial speed of 1.8 m/s?