A block of mass 2kg is released from rest at the top of a smooth incline 5m long that is inclined at 30∘ to the horizontal.
a. (i) Calculate the work done by the gravitational force on the block as it reaches the bottom of the incline.
b. (ii) Using your answer to part (i), determine the speed of the block when it arrives at the bottom.
c. (iii) If the same block were to slide down an identical but 10m long smooth incline at the same 30∘ angle, find the speed with which it would reach the bottom. Show your working.