A hockey puck is sliding on frictionless ice. It slams against a wall and bounces back toward the player with the same speed that it had before hitting the wall. Does the velocity of the hockey puck change in this process? Explain.

Yes the velocity of the hockey puck changed in this process

Explanation:

As we know velocity is the change in the displacement with respect to time. velocity is a vector quantity meaning that it has both direction and magnitude.

In this problem, when the hockey puck slammed against the wall it returned back with the same magnitude as before but its direction of motion was changed which represents a change in velocity therefore, we can conclude that the velocity has changed.

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

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it