A hockey puck is sliding across a frozen pond with an initial speed of 9.5 m/s. It comes to rest after sliding a distance of 37.4 m. What is the coefficient of kinetic friction between the puck and the ice

Explanation:

Given :

Initial speed  

Displacement m

From the kinematics equation,

Where final velocity, in our example it is zero (), acceleration.

From the formula of friction,

Minus sign represent friction is oppose the motion

Where ( normal reaction force )

                                                   ( ∵ )

So coefficient of friction,

Therefore, the coefficient of kinetic friction between the puck and the ice is   0.12 .

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day