A sled of mass 50 kg is pulled along snow-covered, flat ground. The static friction coefficient is 0.30, and?

Question

the sliding friction coefficient is 0.10.

Part D says: Once moving, what total force must be applied to the sled to accelerate it to 3.0 m/s^2? (By the way, I know for certain that I have parts A, B and C correct).

Answer 1

let the force be F , and the sliding friction force be K (coefficient sliding friction = k ) , so

F - K = ma

F = ma + K = ma + kmg = m(a+kg) = 50 (3.0 + 0.1*9.81) = 199 N

Answer 2

Accelerate to 3.0 m/s^2 or to 3.0 m/s? That would make quite a bit of a difference.