Answer:
1. A <em>series circuit </em>is a closed circuit which has all loads connected in a row and there is only one path for the current to flow.
2. The <em>Ohm's Law </em>state that a current flow through a resistor is directly proportional to the voltage across it 
3. A <em>parallel circuit </em>is a closed circuit divided into branches that it has two o more paths for the current to flow and the loads are parallel to each other which mean the voltage across them is the same for all loads.
Remember Newton's second law: F=ma
to get the force in newtons, mass should be in kg and acceleration in m/s^2
conveniently, we don't need to convert units
we just need to multiply the two to get the force
65* 0.3 = 19.5 kg m/s^2 or N
if significant digit is an issue, the least number if sig figs is 1 so the answer would be 20 N
The term is frequency.
The frequency is the number of vibrations per unit of time or the number of waves that passes a point per unit of time.
Every crest (and every trough) represents a pass of the wave so you can count the number of crests in an intervavl of time to find the frequency as the number of crests divided by the time elapsed.
