[jqian]

(Original post by Kirby711)
Well I can't really draw it sorry... But, I can help you.

Essentially the ray refracts away from the normal, because the refractive index of air is less than the water. Apparently there is a bit of reflection, but I don't know why.

There will be always be some reflection even if the incident angle is less than the critical angle, I'm not sure why, but I read it somewhere. Either way, it's really harsh by AQA for forcing you to draw partial reflection to get the 3rd mark (and there's no alternative way to get the last mark).

[Kirby711]

(Original post by jamesp1235)
Hi can someone tell me about projectile motion

And how to uses it thanks


This was posted from The Student Room's iPhone/iPad App

Well you have to look at the motion of the object both horizontally and vertically. In these questions the object may be stationary vertically, but moving horizontally. You need to split the two directions up and use SUVAT equations to calculate what you need. For horizontal motion the velocity is usually constant so you can use speed = distance/time, but you need to calculate the time from the vertical direction. Just remember that gravity is 9.81 ms^2 and you should be fine...

As for the single slit pattern with white light, the central maximum is white and twice as wide as the other maxima, there will be a continuous spectrum and violet will be on the inner.

[aerf]

Has anyone thought about a projectile 6 marker? Stuff you'd have to say would be horizontal and vertical components of flight are completely independent, only time is relative to both. No horizontal acceleration and vertical acceleration entirely due to g. Then they could add on something about air resistance which you'd just say causes deceleration....

[Red Richie]

Please can someone help me on this, on AQA nelson thornes textbook page 181,

- question 2, part A asks me what happens to the interference pattern if the two vibrating dippers creating the waves in the wave are moved apart. And part B asks me what happens to the interference patterns if the frequency of the waves are reduced. Any ideas?

- question 4b, why would signal increase if the reciever is moved towards B?

[jqian]

(Original post by aerf)
Has anyone thought about a projectile 6 marker? Stuff you'd have to say would be horizontal and vertical components of flight are completely independent, only time is relative to both. No horizontal acceleration and vertical acceleration entirely due to g. Then they could add on something about air resistance which you'd just say causes deceleration....

Well, this year's EMPA was on projectile motion, so I guess you could describe that experiment. Although you probably ignore the bit where you had to hit the nail.

[GSB]

Hey guys this is probably a really easy question but I'm having a bit of a derp moment :P It's 5ai) on the June 2009 paper it gives a wave of length 0.50m and then says find the wavelength, the mark scheme says 0.40m but I'm not sure how they got that, any help would be appreciated

[cantthinkofone]

whats partial reflection? and how would you show it on a diagram? it says something about it on january 09 q6 ii on the markcheme

[jqian]

(Original post by GSB)
Hey guys this is probably a really easy question but I'm having a bit of a derp moment :P It's 5ai) on the June 2009 paper it gives a wave of length 0.50m and then says find the wavelength, the mark scheme says 0.40m but I'm not sure how they got that, any help would be appreciated

Their diagram shows 5/4 of a wave, if you look at the entire thing (including the wave to the left of X) then you have 2 wavelengths. However the distance it tells you ignores half a wave (on the right) and one quarter of a wave (on the left), so 2-0.5-0.25 = 1.25. Therefore one wavelength = 0.50/1.25 = 0.4

[AmrinderRai]

Hey guys,
Well I'm looking at some graphs for metal wire, rubber & polyethene.
The rubber goes back to the origin from loading to unloading, is the area between the 2 lines the stored energy in the rubber band?
Also what does the area underneath the unloading line represent?

The other 2 do no go back to the origin, so what does the area between these 2 lines represent?
Still energy stored in material?
Also the area underneath the unloading line?

I know thats quite a few questions... but would really appreciate it, if someone could answer them for me

[amish123]

(Original post by AmrinderRai)
Hey guys,
Well I'm looking at some graphs for metal wire, rubber & polyethene.
The rubber goes back to the origin from loading to unloading, is the area between the 2 lines the stored energy in the rubber band?
Also what does the area underneath the unloading line represent?

The other 2 do no go back to the origin, so what does the area between these 2 lines represent?
Still energy stored in material?
Also the area underneath the unloading line?

I know thats quite a few questions... but would really appreciate it, if someone could answer them for me

The area stored in the rubber band is the area underneath the total area under the loading curve. This shows the energy stored in the rubber band, which could be calculated using the equation 1/2FdeltaL.

The area under the unloading curve is the energy released by the material, don't worry about this it's not in our spec :P

Because the other 2 do not go back to the origin, they have suffered permanent extension so they do not obey Hookes Law. There is no need to worry about the area between the two lines for that i think.

[IAmTheChosenOne]

hey does anyone have notes on mechanics experiments?

I'm dreading tomorrow!

[GSB]

(Original post by jqian)
Their diagram shows 5/4 of a wave, if you look at the entire thing (including the wave to the left of X) then you have 2 wavelengths. However the distance it tells you ignores half a wave (on the right) and one quarter of a wave (on the left), so 2-0.5-0.25 = 1.25. Therefore one wavelength = 0.50/1.25 = 0.4

Thanks a lot man, I was making it much more complicated than it actually was

[aerf]

(Original post by jqian)
Well, this year's EMPA was on projectile motion, so I guess you could describe that experiment. Although you probably ignore the bit where you had to hit the nail.

Sorry but what did you do? I did the resistor ISA instead

[pre-med-guy]

How do you draw this wave?

http://d.pr/i/XAuZ

Is it 2 full waves or 4 full waves?

[jqian]

(Original post by aerf)
Sorry but what did you do? I did the resistor ISA instead

You had a ramp setup for you (the ramp was on a table), you then had a ball bearing and had to let it go from the top of the ramp and make it hit a nail held by a smaller clamp on the floor! You then had to adjust the height of the ramp to see the effect. Was the most tedious experiment I ever did.

[adam17]

When a light ray escapes a glass block, why is the ray partially reflected back inside the block? and how do you know when it does this and when it doesn't? Thanks

[jqian]

(Original post by pre-med-guy)
How do you draw this wave?

http://d.pr/i/XAuZ

Is it 2 full waves or 4 full waves?

2 full waves, a node every 0.16m.

[pre-med-guy]

(Original post by jqian)
2 full waves, a node every 0.16m.

Thanks.

Is the first overtone half of 1 wave cycle?

[Tanmayee]

What degree of accuracy for g should be used if they don't specify? Is it just 9.8 or do we use more decimal places?

[silentlife]

(Original post by Tanmayee)
What degree of accuracy for g should be used if they don't specify? Is it just 9.8 or do we use more decimal places?

On the front of the paper it always says 9.81