How would the story change if it were indeed a mistake (as I am inclined to believe, considering the relatively low quality of many SAT prep books). I assume it might relate the homopolar generator?
By Faraday's law, without any rotation the induced current would be counter clockwise.
Hence it appears that the clockwise rotation of the wire is opposite to what the direction of the induced current would be.
I still don't get how if no current were there this isn't a violation of Farday's...
I assume you mean if the wire rotates in a direction opposite to the motion of charges?
Also, wouldn't it depend on the reference frame? In the frame of the wire there would be a current but in other frames there wouldn't be?
Further, doesn't this violate faraday's law since the magnetic flux...
Homework Statement
A loop of wire and a bar magnet are moving relative to one another. Which motion in the diagrams shown below will NOT induce a current in the loop?
Homework Equations
Lenz's Law: A changing magnetic field can induce a current in a direction that produces its own...
@Mister T
Yeah that seems essentially analogous to andrewkirk's.
Here are the solutions I got for the three variables (found with Mathematica because I'm lazy):
\left\{\left\{T\to \frac{g m_1 m_2 \left(m_2+M\right)}{m_2 \left(m_2+M\right)+m_1 \left(2 m_2+M\right)},a_M\to -\frac{g m_1...
Also, how did you attempt to solve it via conservation of energy / momentum? Because the final velocities are not given, how was it possible to write an expression for momentum/kinetic energy conservation?
Also, I wonder if this problem can be solved by looking at the x-coordinate of the center...
@Mister T
This problem was posed to me by a friend, and he gave me those answer values to check.
I'm guessing the reason why the acceleration is not \frac{g m_1 m_2}{m_1 + m_2} is that the acceleration of both blocks are not the same, as explained above.
The effect of the rails is to keep m_2...
If it helps, here are the specific answers for when m1 = 5, m2 = 10, and M = 15:
T = 28.9 N
Acc. of M = -1.15 ms^-2
Acc. of m1 = 5.78 ms^-2
Assuming the answers are correct, I don't believe your calculated acceleration as found through momentum conservation is valid...
Here are some of the...
That seems reasonable — so the tension on the pulley would then be \frac{g m_1 m_2}{m_1+m_2}, which is the same magnitude of force that accelerates the M + m_2 system.
So is the acceleration of M just \frac{g m_1 m_2}{\left(m_1+m_2\right) \left(M+M_2\right)}?
@andrewkirk Doesn't the fact that the pulley is moving along with M to the left decreases the tension string along the x-direction though? If you look at it from the reference frame of m_1 which is non-inertial, there will be a "pseudo-force" acting towards the right, essentially reducing the...
Since you are given displacement vs. time, the derivative at a point will give you the velocity. Taking a derivative of the velocity graph gives you the acceleration.
Since the displacement graph is roughly quadratic on [0, 4] the second derivative will be a constant.
Thus you can find the...
Draw a freebody diagram, resolving gravity along a set of coordinate axis parallel and perpendicular the the slope. This will give you the the force along the slope due to gravity, which needs to be counteracted by friction.
Homework Statement
[/B]
Consider a half-atwood machine on a cart as below, with mass m_2 attached to M via a frictionless track that keeps it pinned to M but allows it to move vertically. All surfaces (except between the wheels/ground) are frictionless, and the pulley and rope are massless.
If...
This is from question 1 of the F=MA 2012 exam:
Consider a dripping faucet, where the faucet is 10 cm above the sink. The time between drops is such that when one drop hits the sink, one is in the air and another is about to drop. At what height above the sink will the drop in the air be right...