@SIpapiSIpapi
Are you sure it is D? I kept thinking about the graph all night and I seem to remember that it was a position time graph. So, its slope would be velocity, right? Point D was on the equilibrium (Slope=0). So can’t one argue that it wasn’t moving at that instant of time?
@Learner12388 was point D on equilibrium? There was two points on equilibrium, and I thought D was the one slightly below to the left of the next concurrent equilibrium
Both C and D were on the equilibrium. But C was going down. Only E was going up with an instantaneous velocity towards the top.
What was that question^ the first 3?
@ikim16
I only remember the 3rd.
I think I found another explanation. > Either in a pendulum or a spring velocity reaches its maximum value at its equilibrium position. 0 acceleration.
But there is also a restoring force acting on point E. Thus, Acceleration exists at E, but not at D.
Does someone know the correct answer to this question?
@russiaguy
Point E was the one slightly below
I got CAE for the first three if that helps
Do you also remember the photoelectric question? The one with initial frequency and final velocity? Higher, lower, same…
I remember point D being slightly below and to the left, and point E being on the x-axis. So point D was on the graph when it had a positive slope
I really remember E being the one on the left. It was the last question I did.
Does anyone remember the photon question?
What was it?^
It was the frequency and velocity of the photon after impact with an electron
Doesn’t any one know the answer?
well, it deals with the equation: K = hf, where h is plancks constant and f is the frequency. I know you use that but not much else. from your info, I would set hf equal to .5mv^2 since the K’s may be equal to each other.
Again, dont know any answers.
3 Days left…
So close to breaking 700…oh well
780 
I’m shocked, didn’t expect 700
750
780 pretty surprised