Stuck on some Physics, help please!! (Work and Energy)? K this first one im not sure how to do it.. i did the second part, thats because i had all the variables but in this one i dont... ok this is about skeleton racers... the track total height is 104m, in the absence of nonconservative forces, such as friction and air resistance, what would be the speed of a rider at the bottom of the track? ignore initial velocity since its relatively small. and In 2.0min a ski lift raises four skiers at constant speed to a height of 140m. the average mass of each skier is 65kg. what is the average power provided by the tension in the cable pulling... i know what to but i just cant figure out the Work... i know that power = work/time.. so if i could get some help that would be greatly appreciated!