help in physics unit 2 needed !

[shamawi]

http://www.edexcel.com/migrationdoc...m 2000/January 2009/6PH02_01_que_20090115.pdf
question 17 b) please

 

[Arabella_18]

Dude in this one they are asking for fundemental frequency of the wave and they also mentioned in the question that with its fundemental frequency there is one antinode but in the diagram there are 3 antinodes so you divide the frquency 1.5Hz by 3 to get the frequency of one antinode
Hope i helped

 

[shamawi]

lol that simple ? thank youu !

 

[shamawi]

another question , 23) b)

 

[Arabella_18]

Increasing intensity will increase the number of photons arriving per second .Increasing intensity has no effect on photon energy So basically u apply the ratio method 1 : 5*10^-12
4 : x solve it u get ur answer