Question

A hockey puck with a mass of 0.35 kg slides across the ice after a slap shot toward the goal. If the puck decelerates at 7.8 m/s/s, what is the coefficient of Friction between the ice and the puck?

Answer 1

The sliding friction is the net force acting on puck in horizontal direction,
Therefore, from Newton's 2nd law of motion,
f = ma 
f = sliding frictional force = μmg 
μ =coefficient of sliding friction, m = mass of puck, a = deceleration = 7.8 m/s²
∴ μmg = ma
∴ μ = a/g = 7.8/9.8 = 0.795
Therefore, the coefficient of friction is 0.795