A person on a sled coasts down a hill and then goes over a slight ...

[SO00]

A person on a sled coasts down a hill and then goes over a slight rise with speed 2.7 m/s. The top of this rise can be modeled as a circle of radius 4.1 m. The sled and occupant have a combined mass of 110 kg.
 
  If the coefficient of kinetic friction between the snow and the sled is 0.10, what friction force is exerted on the sled by the snow as the sled goes over the top of the rise?

Question 2

What is the nuclear radius of 90Sr?
 
  A) 4.0  10-15 m
  B) 1.2  10-15 m
  C) 1.1  10-13 m
  D) 5.4  10-15 m
  E) 3.3  10-13 m

[Natalie4ever]

Answer to Question 1

88 N

Answer to Question 2

D

[SO00]

Gracias!

[ghepp]

TYSM