Answer:B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
Explanation:
We take the derivative of Ohm's law with respect to time: V = IR
Using the product rule:
dV/dt = I(dR/dt) + R(dI/dt)
We are given that voltage is decreasing at 0.03 V/s, resistance is increasing at 0.04 ohm/s, resistance itself is 200 ohms, and current is 0.04 A. Substituting:
-0.03 V/s = (0.04 A)(0.04 ohm/s) + (200 ohms)(dI/dt)
dI/dt = -0.000158 = -1.58 x 10^-4 A/s
Answer:
Explanation:
The diagram has a fairly simple explanation. In the top diagram, the space between the particle is increasing. That means that acceleration is increasing. The bottom diagram shows just the opposite. The particle starts off making large "distances" between where the particle is recorded and then the distances between recordings lessens and the particle is slowing down.
Rule: the greater the "distance" between dot positions, the greater the acceleration, because the speed is large.
Top diagram: increasing distance between dots = larger speed. The distance becomes greater as the particle moves to the right.
Bottom diagram: starts off large and decreases as we move from left to right = - acceleration.
Answer: A and B
Explanation:
took the test:) hope this helps
