Question

Jim wishes to push a 100. N wood crate across a wood floor. What is the minimum horizontal force that would be required to start the crate moving?

Answer 1

any friction coefficient isn't given?

Answer 2

i think its 0.42

Answer 3

to start the crate moving you need to apply the force that is greater or equal to maximum frictional force. in other words the force required must be equal to that frictional force.
Do you know what is the value of that frictional force?

Answer 4

well, that force is simply:
\[F=\mu W=0.42*100=42N\]