If the pulling is done parallel to the floor with constant velocity, then the box is in equilibrium. In particular, the weight and normal force cancel, so that
<em>n</em> = 38 N
The friction force is proportional to the normal force by a factor of 0.27, so that
<em>f</em> = 0.27 (38 N) ≈ 10.3 N
and so the answer is D.
A and C is the correct one
You<span> should </span>test<span> FC and PH as soon as </span>you<span> take the sample</span>
Because it eats plants and animals.
