Complete question is;
Selena drew a diagram to show how current moves in a loop of wire that is placed between two magnets. At top left a piece of magnet labeled N and at top right a piece labeled S. Between these a square coil of wire with green arrows at its ends away from the magnets pointing away from the magnets. Red arrows point from N to S. Which best explains how Selena can correct her error?
A) She can change the magnets so like poles are facing each other.
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
C) She can change the arrows so they show the magnetic field reversing direction between the magnets.
D) She can change the magnetic poles so they are both on one side of the loop.
Answer:
B) She can change the arrows so they show current traveling in opposite directions on the sides of the loop.
Explanation:
Since the direction of the arrows point north and south whereas the magnets are east and west, it means the arrows are not pointing in the correct direction. To correct it she will have to make sure the arrows are pointing in opposite directions of the magnet via the sides of the loop.
(a)
The formula is:
∑ F = Weight + T = mass * acceleration
as the elevator and lamp are moving downward, I choose downward forces to be
positive.
Weight is pulling down = +(9.8 * mass)
Tension is pulling up, so T = -63
Acceleration is upward = -1.7 m/s^2
(9.8 * mass) + -63 = mass * -1.7
Add +63 to both sides
Add (mass * 1.7) to both sides
(9.8 * mass) + (mass * 1.7) = 63
11.5 * mass = 63
mass = 63 / 11.5
Mass = 5.48 kg
(b)
Since the elevator and lamp are going upward, I choose upward forces to be
positive.
Weight is pulling down = -(9.8 * 5.48) = -53.70
Acceleration is upward, so acceleration = +1.7
-53.70 + T = 5.48 * 1.7
T = 53.70 + 9.316 = approx 63 N
The Tension is still the same - 63 N since the same mass, 5.48 kg, is being accelerated
upward at the same rate of 1.7 m/s^2
<span> The masses have no inertia about their own CM, and "the object" is the two masses. </span>
<span>1. Icm (at point A) = 2mr^2
hope this helps</span>
A scientific law is absolute, it cannot be proven wrong. A scientific theory is like a belief, it has been proven but can also be argued or disproven.
