Recent content by Alche

But in the question it is only mentioned about permutations of the letters, they have no where asked about the combination. I think I was not able to grasp what it was asking earlier, now I got it. If am wrong then please correct me.

Thanks for replying. I got it.

Homework Statement How many permutations of the letters a, b, c, d, e, f, g have either two or three letters between a and b? b _ _ a is also very much possible.Homework Equations nPr= n!/(n - r)!, where n >= rThe Attempt at a Solution For this question there can be 4 cases which are as...

Even I think the same. :smile: I think we measure the angle with respect to the normal because by doing so we can explain many phenomenon that happens in the nature due to reflection and refraction of light.May be by measuring the angle horizontally we won't be able to explain those phenomenon...

Why do we measure the angle of incidence or reflection (or say refraction even) w.r.t normal to the surface and why not w.r.t the horizontal surface?

Thanks Sir :smile: focal length of the lens f = R/2, where R is the radius of curvature of the given lens

Well, I think when we bisect the convex lens vertically its radius of curvature becomes R/2 so the focal length becomes 2f. And I am sure the same things happens with concave lens too :-p:smile:

1)Why when a convex lens having radius of curvature R, focal length f and refractive index μ is bisected horizontally along the principal axis its focal length remains the same, whereas when it is bisected vertically focal length becomes 2f? Does the same thing happens in the case of...

One of my friend asked me about this, I couldn't find anything about it in books and google so posted it here. Even I don't have any information about this:confused:

what is wedge constant and where and how to use it?

frame-of-reference! the force exerted is the pseudo force

Well the nut will land or not on the Earth depends on where it is located, it will surely land on the Earth if its inside the satellite( yeah I agree that, for that satellite too has to land on the earth). It is also depended on where satellite is located, if it is located far away from the...

I think it has, but it will be different for different planets and stars since they have different masses, so they'll be attracting Earth towards themselves with different magnitude of force because, g(acceleration due to gravity) = √GM/R2, where M & R are the mass and the radius of the body...

While reading gravitation chapter I got some doubts, and that I am posting here. 1) Is there any meaning of "Weight of the Earth"? 2)At noon, the sun and the Earth pull the objects on the Earth's surface in opposite direction. At midnight the sun and the Earth pull these objects in the...

Can you tell which point has vertical velocity for second question