Question

1) Let's practice calculating the frictional force of a skier on old "woody" skis and wet snow. The skier has a mass of 58 kg. The coefficient of kinetic friction of wood skis on wet snow is 0.1 Notice there are no units for the coefficient of friction. What is the kinetic frictional force between the wood skis and the snow?

Answer: ??

2) Do you remember Newton's 2d Law? F = ma? What is the magnitude (meaning we are disregarding the direction) of the acceleration of the kinetic frictional force?

Answer: ??

3) The two man bobsled has a maximum mass allowed is 390 kg. We'll use that. Here is a stunning number: The coefficient of kinetic friction between the bobsled runner and the ice is .0073! Since there are two runners, we will multiply that number by 2 and get .0146. Calculate the normal force of the bobsled: Fn

Answer: ??

4) The two man bobsled has a maximum mass allowed is 390 kg. We'll use that. Here is a stunning number: The coefficient of kinetic friction between the bobsled runner and the ice is .0073! Since there are two runners, we will multiply that number by 2 and get .0146. Calculate the the kinetic frictional force opposing the motion of the bobsled.

Answer: ??

5) Our 390 kg bobsled with the coefficient of kinetic friction of .0146 opposing it's motion is finishing it's run and is going 42 m/s (close 93 mph!). If this massive object, going at this huge speed (lots of kinetic energy) we're going to let this bobsled coast to a stop. Final speed is 0 m/s. Calculate the change in kinetic energy.

Answer: ??

6) Knowing the change in kinetic energy from Q10, knowing the frictional force from Q9, how far would this bobsled go (ignoring drag forces we'll learn about in the next section) before coming to rest?

Answer: ??

Answer 1