The EM spectrum has no limits. Any frequency you can imagine
is the frequency of some electromagnetic radiation somewhere.
closed and unsecure circuit
The net force = sum of all forces acting on the body
If we take left side as -ve and right side as +ve,
then,
The net force here would be equal to,
10N + (- 3N)
= 7N.
Therefore, a net force of +7N ( + indicates it's moving towards right) is acting on the book of mass 2kg.
A would be the wavelength, C would be a crest, D would be the amplitude, leaving B which is the trough.
