Phy P2 urgent help please!

[azfar kashif]

May June 07 Phy P2

Can anybody plz tell me how did u get to the conclusion of Q2 part (d)..... couldn't understand much from the mark scheme! Explain plz.... thanku!

 

[Amanina]

use equation s=ut+1/2at^2 to answer this question.

s= 1/2 (2.46X10^15) ((2.4X10^-9)^2)
s = 7.08 X 10^-3m = 0.708cm

this mean that at the end of the plate, electron do not hit the plate as it traveled 0.708cm vertically. which is less that (1.5/2)=0.75cm
if the electron travel >0.75, for sure it will hit the plate.

hope this helps.

 

[azfar kashif]

Thanks a lot! Got it.....

 

[MAVtKnmJ]

I still didn't get this, what is 0.75???

 

[Amanina]

I still didn't get this, what is 0.75???

separation between plates is 1.5 right? distance between electron to plate is half of it. which is 0.75

 

[azfar kashif]

I have another problem!!! Can u please tell me how to do June 06 P2, Q6, part (c)????

 

[Amanina]

@ azfar kashif,
we know that the wavelength is 64.8cm. so, from a node to an antinode, it cover only 1/4 the wavelength. means 1/4 of 64.8cm = 16.2 cm

te antinode should be 16.2cm above the water surface
or u can also answer (16.2-15.7)=0.5cm above the top of tube.