The Student Room Group

Scroll to see replies

I got ABCB or something like that... definitely no D and 2 of either B or C.

Phasors: E was 3-o-clock, G was 10:30.

Kinetic energy by factor of 4: The wavelength doubles I believe.

Distance of diver - 4.32. Explain 4.7 please.
Original post by CrystalPlanet
Kinetic energy is inversely proportional to wavelength squared. So rearranging the formula with kinetic energy reduced by a factor of 4 (i think it was reduced) should double wavelength.

Dom has it; though I used a formula from A2 physics, sort of cheating haha

It's Kinetic energy= h^2/2mW^2

(w is wavelength as I don't know how to put greek letters)

Ahh thank god!! haha
Original post by Minecraft27
I got ABCB or something like that... definitely no D and 2 of either B or C.

Phasors: E was 3-o-clock, G was 10:30.

Kinetic energy by factor of 4: The wavelength doubles I believe.

Distance of diver - 4.32. Explain 4.7 please.


Does anyone have access to the paper?

The distance was 4 something.

Its velocity was ~9.2-9.6, it was one or the other. The time period was 0.96 seconds I think, it was just under 1.

So the true answer lies somewhere in this region.
Original post by DomStaff
Does anyone have access to the paper?

The distance was 4 something.

Its velocity was ~9.2-9.6, it was one or the other. The time period was 0.96 seconds I think, it was just under 1.

So the true answer lies somewhere in this region.

I got a time of 0.92 seconds and a velocity of 9.4.
For the question where the wavelength doubles, I had a mind blank and the maths seemed to escape me, i wrote all the relationships down and got wavelength increase, however I did use any numerical dat e.g. halves or doubles. Will I still get a mark for the right idea?
Original post by Knowing
I got that it pointed to 3 o'clock


9


Posted from TSR Mobile
Original post by Minecraft27
I got a time of 0.92 seconds and a velocity of 9.4.


Ah that may have been it! I can just remember it being a time period just under 1.
For the flute question which asked whether the flute needed to be longer or shorter, what did the question say?
And also how many marks was it worth please??


No it is 3.

Phasors rotate anticlockwise. It was 3/4 of a rotation.
Original post by DomStaff
Does anyone have access to the paper?

The distance was 4 something.

Its velocity was ~9.2-9.6, it was one or the other. The time period was 0.96 seconds I think, it was just under 1.

So the true answer lies somewhere in this region.


I used 1/2at^2 as u=0 and a=-9.8

S=1/2*(-9.8)*(0.94)^2=-4.33m
Original post by CrystalPlanet
I used 1/2at^2 as u=0 and a=-9.8

S=1/2*(-9.8)*(0.94)^2=-4.33m


I can't remember at all!

edit:
That does ring a bell actually, the 4.3 aspect but I am not sure exactly what I wrote/measured the period as. 0.94 does sound familiar
Can't even remember any of the diver questions :s-smilie:
Reply 392
What did people put for the 80% efficiency of the NiMH battery being a disadvantage?
Original post by STATER
What did people put for the 80% efficiency of the NiMH battery being a disadvantage?


Energy wasted as friction heats up battery so can get dangerously hot.
electrical energy generated in power stations wasted so using up fossil fuels unnecessarily.
Tbh I wasn't really sure so I made it up :/
Reply 394
Original post by Carla Huynh
Energy wasted as friction heats up battery so can get dangerously hot.
electrical energy generated in power stations wasted so using up fossil fuels unnecessarily.
Tbh I wasn't really sure so I made it up :/

Ahhh good point about the heat. I said it would take longer to charge and would discharge faster relative to other batteries, as the previous part mentioned it being the efficiency in charge and discharge. Seems weak for both marks though.
Oh yeah was the energy dissipation of the NiMH battery 10,000J or 40,000J. I couldn't remember if dissipation is losses or useful energy.
Original post by MasterOfTheSwag
Oh yeah was the energy dissipation of the NiMH battery 10,000J or 40,000J. I couldn't remember if dissipation is losses or useful energy.


10000J
Original post by DomStaff
10000J


Thank Christ for that
Original post by MasterOfTheSwag
Thank Christ for that


Hahahahahah
Original post by DomStaff
10000J


Original post by MasterOfTheSwag
Thank Christ for that


Crap.

(should only be a mark off, right?)