Answer:
10.0 N West
Explanation:
Imagine East is positive and West is negative. Essentially now we have 2 forces pulling opposite each other on the same plane, so we can add them up.
F1=20N
F2=-30N
F1+F2=Net Force
20+(-30)=-10
Therefore the Net Force is 10N West.
Answer:

Explanation:
Given that,
The instantaneous current in the circuit is giveen by :

We need to find the rms value of the current.
The general equation of current is given by :

It means, 
We know that,

So, the rms value of current is 2.12 A.
Explanation:
The third class lever cannot magnify our force because in third class lever the effort it between the load and the fulcrum. Also, in this type of lever no matter where the force is applied, it is always greater than the force of load. Hence, That type of lever cannot magnify our force.
You can test if it’s true by holding a pencil in mid air over a table and the table is supposed to be the unbalanced forced that stopped the pencil from moving at the constant velocity it was going by.