Study guide for quiz 5 1) A 50 kg skier stands pm a slope with an angle of 30 de
ID: 1876102 • Letter: S
Question
Study guide for quiz 5 1) A 50 kg skier stands pm a slope with an angle of 30 degree from horizontal. The coefficient of kinetic friction is 0.05 mac coefficient of static friction is 0.1. Find a) can skier start to move? b) if the skier can move, what is the acceleration, c) what is the speed of the skier after 6 se from start. 2) A coin is in rest in a horizontal ceramic plate. A person is trying to lift the plate at one edge and the plate slowly starts to tilt. At the angle of 20 degree from horizontal, the coin move. Calculate a) the static friction coefficient between the coin and the plate, b) if the coin has a mass of 10 g, what is the static friction force between the coin and the plate when angle of the plate is tilted 10 degree from horizontal.Explanation / Answer
1)
The maximum friction force that the skier can fell will be
f=0.1*50*9.81*cos30
f=42.4785N
And, the maximum downward force will be
F=50*9.81*sin30
F=245.25N,
So yes the skier can move, as the downward force is greater than the friction force.
(b)
Accleration will be
F-f=ma
245.25-42.48=50a
a=4.055m/s2
(c)Now applying first equation of motion,
v=u+at
v=4.055*6
v=24.33m/s