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How much motion energy does an 0.5-kg hockey puck sliding across the ice rink at 4 m/s have?

User Rax Wunter
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1 Answer

4 votes

Answer:

A hockey puck is given an initial speed of 5.3 m/s . If the coefficient of kinetic friction between the puck and the ice is 0.05, how far does the puck slide before coming to rest? Solve this problem using conservation of energy.

Step-by-step explanation:

This is easy to do and it is very cool how it works.

Force here is what converts the kinetic energy to heat by friction and slows the puck

fu = coefficient of Kinetic friction

g = is the acceleration of gravity

Fu*g = a.

So friction force on the puck is the acceleration of gravity times the coefficient of kinetic friction and the acceleration force is made negative here because it is slowing down the puck. .

Puck friction to negative acceleration

fu=0.05

g = -9.81m/s^2

so

a = 0.05 * -9.81m/s^2 = -0.4905 m/s^2

For the moving puck

Velocity = v = u + (a*t) | u=initial velocity

So

Time = t = (v-u)/a

Distance = d = t *(v + u)/2

So

Distance d= ((v-u)/a) * ((v+u)/2)

This becomes d = (v-u)(v+u)/2a

Plugging in the numbers

d= (0 - 5.3)(0 + 5.3)/(2*-0.49.5) =28.63 meters

User Johnny Bou
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