Question

A 160g hockey puck initially moving with a speed of 5.00 m/s slides for 25.0 m across the ice sheet of a hockey rink before coming to rest.
What is the acceleration of the puck as it moves?

What is the net force on the puck as it moves?

Draw a free body diagram. label each force.

What law of physcis can you use to relate the normal force on the puck to its weight? Derive the relation and evalutate the normal force.

Determine the coefficient of friction from its defining relation and what you determined above.

Answer 1

a)
Using the relation, v² - u² = 2as,
Where v is the final velocity, v = 0, u is the initial velocity, u = 5 m/s, a is the acceleration and s is the distance travelled.
a = (v² - u²) / 2s
= (0 - 25) / (2 x 25)
= - 0.50 m/s²

b)
Net force, F = ma
= 0.160 x 0.5
= 0.08 N

c)

d)
For every action, there is equal and opposite reaction.
Weight = Normal force
mg = N
N = 0.16 x 9.81
= 1.57 N

e)
Frictional force = N,
Where is the coefficient of friction.
This is the same force that stops the puck
F = N
= F/N
= 0.08 / 1.57
= 0.051