Answer: A)
Explanation: when an electron is placed in a magnetic field, it experiences a force.
This force is given below as
F=qvB*sinθ
F = force experienced by charge.
q = magnitude of electronic charge
v = speed of electron
B= strength of magnetic field
θ = angle between magnetic field and velocity.
What defines the force exerted on the charge is the angle between the field and it velocity.
If magnetic field is parallel to velocity, then it means that θ=0° which means sin 0 = 0, which means
F = qvB * 0 = 0.
The charge being at rest has nothing to do with the angle between magnetic field strength and velocity.
1) B. Energy is the ability to do work
2) C. Energy is conserved, it just goes from one form to another.
3) Work = Force x displacement
= 300 x 100 = 30,000 Joules
4) leaning a brick because no displacement is taking place.
5) They change the amount/strength or direction of the force needed.
6) Less force is needed and applied over a longer distance.
7) Heat is the flow of thermal energy from one object to another.