is that even legit reasonin??The disc is moving in same direction relative to the magnetic field. This creates creates a DC current. According to Lenz's law, the current will oppose the change in flux that created it. The disc is moving toward brush Y, therefore the current will flow from Y to X.
Haha. I couldn't illustrate my point very eloquently. MY reasoning was that the, the x brush is on the axel and the disc is rotating toward the y brush. Thats how I reasoned it in my head. I can't say for sure if this is correct, but it's the conclusion I came to.is that even legit reasonin??
When the current is turned on in X, at the start a magnetic field is induced to oppose the increase in voltage, and therefore generate a back EMF, however it will eventually reach a constant voltage as it is a DC circuit and there will eventually be no magnetic field. A similar field will be created to oppose the voltage change when the switch is turned off but it will be in the opposite direction. Because there is only a changing magnetic field when the switch is turned off and on and not while it is operating at full voltage, a current will only be induced in coil Y when this field is changing, so therefore only when the switch at X is turned on and off. The induced voltage in Y when the switch is turned on will be in the opposite direction as that induced when the switch is turned off, so it would be A.And another fucked question. WHY IS THE ANSWER A? not B??:
What are the approimate work functions of both these metals??? is it where the lines start???
So is metal y at 9 and metal x at 4??
I though the work function is where the line meets the "KINETIC ENERGY" axis (y-intercept), and the absolute value of that is the work function??
Yes you're correct.
What are the approimate work functions of both these metals??? is it where the lines start???
So is metal y at 9 and metal x at 4??
I though the work function is where the line meets the "KINETIC ENERGY" axis (y-intercept), and the absolute value of that is the work function??
The line has the formula: EK = hf - W
What are the approimate work functions of both these metals??? is it where the lines start???
So is metal y at 9 and metal x at 4??
I though the work function is where the line meets the "KINETIC ENERGY" axis (y-intercept), and the absolute value of that is the work function??
What are the approimate work functions of both these metals??? is it where the lines start???
So is metal y at 9 and metal x at 4??
I though the work function is where the line meets the "KINETIC ENERGY" axis (y-intercept), and the absolute value of that is the work function??
This is like the 5th time this week LOLThe line has the formula: EK = hf - W
So yeah, when the value of the work function occurs when the frequency is zero, i.e. the y-intercept (as you said).
But, we can also find it out using the x-intercepts. When EK = 0, W = hf.
The THRESHOLD FREQUENCY for Metal X is at 4 x 10^-14 and for Metal Y is at 9 x 10^-14. Therefore, the WORK FUNCTION for Metal X is h * (4 x 10^-14) and the work function for Metal Y is h * (9 x 10^-14).
(LOL, NEVER MIND AGAIN - done above twice)
ikr, ffs, need to get faster at typing up my answers, lolThis is like the 5th time this week LOL
Its where it meets the y-axis, so if you have the equation hf=hf0+KE and you re arrange it to give your variables as KE and f, then you get KE=hf-hf0 then in the form y=mx+b, you get the y intercept to equal -hf0, which is also equal to the work function, and the gradient is equal to h from mx=hf
What are the approimate work functions of both these metals??? is it where the lines start???
So is metal y at 9 and metal x at 4??
I though the work function is where the line meets the "KINETIC ENERGY" axis (y-intercept), and the absolute value of that is the work function??
my bad.
Why is it B?
i thought it would be an INCREASING straight line.
Because it is a radial magnetic field and THETA is always 0 degrees it must be some form of straiht line, but i thought if it speeds up then the torqu needs to be larger
"radial" means constant torque, hence the straight line for torque. Not good enough at phys to explain in depth, sorry!
Why is it B?
i thought it would be an INCREASING straight line.
Because it is a radial magnetic field and THETA is always 0 degrees it must be some form of straiht line, but i thought if it speeds up then the torqu needs to be larger