- #1

santoki

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## Homework Statement

A man is pulling a 40.0 kg crate across a level floor with a horizontal force, and the coefficient of kinetic friction is μk = 0.59 for the crate and the floor.

14. What is the normal force acting on the box?

a) 231 N

b) 340 N

c) 196 N

d) 392 N

15. What horizontal force must the man apply to get the crate to accelerate at 2.0 m/s2 ?

a) 311 N

b) 231 N

c) 81 N

d) 40 N

**2. The attempt at a solution**

For 14:

N = mg = (40.0)(9.8) = 392N

For 15:

N-F

_{x}= ma

_{x}

392 - F

_{x}= (40.0)(2.0)

F

_{x}= 312N

but there's no 312N there and I didn't even incorporate the μk?