A roller coaster cart of mass 500 kg starts from rest at the top of a hill, 40 meters high. At the bottom of the hill, friction and air resistance cause the cart to lose 20% of its mechanical energy. 1. Calculate the cart's potential energy at the top of the hill. 2. What would be the theoretical velocity at the bottom of the hill without energy losses? 3. What is the actual velocity at the bottom, considering the 20% energy loss? 4. What is the efficiency of the roller coaster in converting potential energy to kinetic energy?

A 20m rope is hanging over the edge of a 50m building. Attached to the end is 2 kg bucket carrying 30kg of sand. There is a whole in the bucket that allows the sand to leak out at 0.5 kg/m. Disregarding the rope, how much work is done lifting the bucket to the top of the building? Show all work. Include units. Method of solving: fnint(), rounded to nearest whole number or Fundamental Theorem. Your choice

How much work is done by boy pulling his sister 33m in a wagon as shown in the figure below? (A) no friction acts on the wagon and mass of wagon and girl is 35kg (assume d=33m and F=56N.) (B)Assume a coefficient of friction of 0.025. How much word is done by: (i) The net force (ii) friction. (Iii) normal force

Question 7: Indicate which of the forces do not perform work on the box and explain why: FBD KD WEIGHT PULLING FORCE mv FRICTIONAL FORCE NORMAL FORCE