[Rehaan_genius]

Who can solve this?
I think its not a difficult one, only concept based, but I get stuck with it!



Two inclined planes OA and OB having inclination 30degrees and 60degrees with the horizontal respectively intersect each other at O, as shown in the figure.
A particle is projected from point p with velocity u=10 under root 3 m/s along a direction perpendicular to plane OA. If the particle strikes plane OB perpendicular at Q (take g=10 m/s^2) then,
a) find time of flight from P to Q.(Ans:2sec)
b) The velocity with which the particle strikes the plane OB.(Ans:10m/s)
c) The height h of point P from the ground.(Ans:5m)
d) the distance PQ.(Ans:20m)

[Rehaan_genius]

actually what I did for the first part is:

I find the time when the initial velocity component becomes perpendicular to final velocity component which comes out to be u/gsin60=2 sec.
but remaining parts..? I have no clue..!

[Rehaan_genius]

I just want to know which thing can I use to solve the remaining parts. I want to try myself!

[Rehaan_genius]

Hey administrator! Help me! No one has solved it yet!

[galactus]

Wouldn't part b just be

[Rehaan_genius]

Actually galactus! I don't get your hint!

[Rehaan_genius]

I got a hint which is;
just rotate the axes along AO and OB means now AO is y-axis and OB is x-axis, but I am still not able to solve it!

[Rehaan_genius]

Hi guys! I solved part a as follows;

[Rehaan_genius]

And part c as follows;

[ISneezeFunny]

Part b

As the hint says, rotate so that now AO becomes a tall building, and OB is the ground.

Now, you've got a "if I kick a ball horizontally off a building" problem.

You found out that AO is 10m

And the entire thing took 2 seconds.

... which, by my math, should hit at 20 m/s...

... am I missing something here? I haven't checked your math for prev parts... so I'm not entirely sure, but if you're getting the right answers...

[Rehaan_genius]

Part (b) is solved!



And part (d) is also solved!