Physics AS level, need help in 3 mcqs, pleaseeeee, I would very much appreciate it!!

[Peter Check]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w10_qp_11.pdf

question 5,7 and 24

for question 5 I have no idea how to go about it!
In 7, dusn't the horizontal component of the ball always remain constant?
How is it C for 24? Isn't the point going down rather than up at C?

 

[SalmanslK]

For Q5 => 60/3000 = 0.02 sec.(period for one wavelength). 0.02/10 (time/cm for one wave to appear on a 10cm screen) . 2*10^-3 / 2 (divide by 2 for 2 Waves to appear) => 0.01 scm^-1 OR 10 ms/cm.

for Q7 => as there is air resistance Horizontal will decrease and will NOT be constant so possibilities are A OR B. We know when dere is air resistance first the object accelerates until Weight = Air Resistance.

For Q24 => Properties Of A WAVE.

guess this is helpful.