Her mass stays the same and her weight changes
Answer:
The net torque about the pivot is and the answer is 'c'
c. 
Explanation:

The torque is the force apply in a distance so it is the moment so depends on the way to be put it the signs so:





Now to find the net Torque is the summation of both torques


Answer:
The net force on the box is 2 N to the left.
The box will move to the left.
The acceleration on the box is 0.5 m/s^2 to the left.
Explanation:
Let's say movement to the right is positive and left is negative.
Bob: +10 N
John: -12 N
Add those together and you get a net force of -2 N, and the negative sign means that the box is moving to the left.
For the acceleration:
Fnet = ma
-2 = (4 kg)a
a = -0.5 m/s^2
Again, the negative sign in this answer means the box is being accelerated to the left.
I'd say A. because an inference is a guess/estimate. You can assume that the egg rolled off the kitchen but you know that C and D are true.