Question

A boy exerts a 36-N horizontal force as he pulls a 52-N sled across a cement sidewalk at a constant speed. What is the coefficient of kinetic friction between the sidewalk and the metal sled runners? Ignore air resistance.

Answer 1

0.69

Step-by-step explanation:

Sum of the forces on the sled in the y direction:

∑F = ma

Fn - 52 N = 0

Fn = 52 N

Sum of the forces on the sled in the x direction:

∑F = ma

36 N - Fn μ = 0

Fn μ = 36 N

μ = 36 N / Fn

Substitute:

μ = 36 N / 52 N

μ = 0.69

Answer 2

cofficient of kinetic friction is 0.6923

Step-by-step explanation:

Given Data

Coefficient of kinetic friction μk =
`f_(k)`/N where fk is force of kinetic friction and N is normal reaction;

we have N = 52 N, and fk = 36 N ;

μk =
`f_(k)`/N

= 36/52

= 0.6923

cofficient of kinetic friction is 0.6923.