Weight (lb) 70 170 Weight (N) 0.18 80 Height of single step (m) Number of steps climbed Total height climbed (m) 42 19 Time to walk stairs (s) Time to run stairs (s) Walking Running Work (J) Power (W) Power (hp)

Question 10) Sasha pushes a 15 kg cart full of donated books through a 5.0 m Tong starting area. The cart is then released and must reach the top of the hill 2.5 m in neight, as shown in the diagram below. He must apply enough force on the cart so that the cart is able to travel along the 8.0 m path and reach the top of the hill. The force of friction between the 8.0 m path and the cart is 11.0 N. What minimum force on the cart in the starting area is required to get it to the top of the hill?

A child pulls a sleigh up the incline as shown below. The work done by gravity on the sleigh during this motion is mgL cos? mgL sin? -mgL cos? -mgL sin? none of above

What is the power developed by the student running the stairs?  1N = 0.225 lb 1 hp = 746 watts  a) 0.07 hp b) 1.53 hp  c) 0.32 hp  d) 0.77 hp