-- reduce the length of a wire to 1/2 . . . cut the resistance in half
-- reduce the diameter to 1/4 . . . reduce the cross-section area by (1/4²) . . . increase the resistance by 16x .
-- R2 = (R1) · (1/2) · (16) = 8 · R1
<em>-- R2 / R1 = 8</em>
Answer:
Explanation:
Situations in which an electron will be affected by an external electric field but will not be affected by an external magnetic field
a ) When an electron is stationary in the electric field and magnetic field , he will be affected by electric field but not by magnetic field. Magnetic field can exert force only on mobile charges.
b ) When the electron is moving parallel to electric field and magnetic field . In this case also electric field will exert force on electron but magnetic field field will not exert force on electrons . Magnetic field can exert force only on the perpendicular component of the velocity of charged particles.
Situations when electron is affected by an external magnetic field but not by an external electric field
There is no such situation in which electric field will not affect an electron . It will always affect an electron .
Good morning.
We have that:

, since we have rest in the inicial time.
The acceleration can be found with Newton's Law:

Now we put the acceleratin in the velocity equation:

We want the force, so, let's isolate
F:
Answer:
person is accelerating downwards
Explanation:
We are told that the force of the person standing on the elevator is 800 N acting downwards.
We are also told that the upward force of the elevator on the person is 600 Newtons.
This means that Upward force is lesser than downward force and thus the person is accelerating downwards