A hockey puck is hit on a frozen lake and starts moving with a speed of 13.80 m/s. Exactly 5.1 s later, its speed is 7.80 m/s.
(a) What is the puck's average acceleration?
m/s2
(b) What is the coefficient of kinetic friction between the puck and the ice?
Vf=Vi+at solve for a
but force=mass*a
or mu*mg=ma
or a= mu*g
To find the average acceleration of the puck, we can use the equation:
Average acceleration (a) = (final velocity - initial velocity) / time
(a) Given:
Initial velocity (u) = 13.80 m/s
Final velocity (v) = 7.80 m/s
Time (t) = 5.1 s
Using the formula, we can calculate the average acceleration:
a = (v - u) / t
a = (7.80 m/s - 13.80 m/s) / 5.1 s
a = -6 m/s / 5.1 s
a ≈ -1.18 m/s^2
Therefore, the puck's average acceleration is approximately -1.18 m/s^2.
To solve for the coefficient of kinetic friction between the puck and the ice, we need to use the equation that relates the coefficient of friction (μ), normal force (N), and the acceleration due to gravity (g):
μ = (m * g) / N
However, we do not have the mass (m) of the puck or the normal force (N), so we need additional information in order to calculate the coefficient of kinetic friction.