A dockworker loading crates on a ship finds that a 34.0-kg crate, initially at rest on a horizontal surface, requires a 72.0-N horizontal force to set it in motion. However, after the crate is in motion, a horizontal force of 51.0 N is required to keep it moving with a constant speed. Find the coefficients of static and kinetic friction between crate and floor.

Question

For coefficient of static = 72 / (34 x 9.81) = 0.22

For coefficient of kinetic = 51 / (34 x 9.81) = 0.15

Turned out my answers were wrong. Can someone explain what I did wrong?

Answer 1

Perhaps need three significant figures
for example
72.0 not 72 / (34.0*9.81) = 0.21587.. = 0.216