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dude it is written that sun is assumed to be a black body

brilliant.
btw this is the first solved problem of the fiitjee study package.

Is the ans (A)

plz solve Q46 , 47, 48 on pg 101, HC Verma pt2

Q) In ambiguous case prove that the circumcircles of the two triangles are equal

brilliant dude. Try the others also plz

which compund will absorb the maximum amount of heat when dissolved in the same amount of water at 25 deg Cent.

(a) HCl (delta H = -17.74)

(b) HNO3(delta H= -7.85)

(c) NH4NO3(DELTA H= +16.08)

(D) NACL(DELTA H = 1.02)

Ok I'm having a real tough time solving the problems of these chapter, I've got lots of doubts which i am writing here please solve as much as you can.

1) if in a triangle ABC a⁴+b⁴+c⁴ = 2c²(a²+b²) prove that angle C is either 45 or 135

2) If I_nis the area of an n sided polygon inscribed in a circle of unit radius and O_nbe the area of the polygon circumscribing the circle prove that

I_n= O_n/2 [1+ sqroot(1-(2I_n/n)²)]

3) if the tangents of the angles of a triangle are in AP prove that the squares of the sides are in the ratio x²(x²+9) : (3+x²)²: 9(1+x²); where x is the tangent of the least or the greatest angle

4) prove delta <= 1/4 (sqroot(a+b+c)abc)

5) prove (acos²A/2 + bcos²B/2 + ccos²C/2) / (a+b+c) <= 3/4

6) If a²,b²,c² are in AP , then cotA,cotB,cotC are in ?

7) IN AN ACUTE ANGLED TRIANGLE THE LEAST VALUE OF SECA+SECB+SECC IS?

please help!

Calculate the temperature of the sun given intensity, distance from the earth and radius as I,d,R.

it is known that radiation emmited by any body does not affect the medium involved.

The sun is a radiating body but still it warms the atmosphere?Explain?

On mixing the two gases

U_mix=

U_gas1+

U_gas2

(n₁+n₂)Cv_mix

T = n₁Cv_gas1

T + n₂Cv_gas2

T----(i)

now it is given that the

_mix=3/2

we have Cv_mix=R/

-1

Cv_mix=2R(on putting gamma=3/2)

also, Cv_gas1=3R/2

and Cv_gas2=5R/2

on substituting all these values in equation 1 we get

(n₁+n₂)2R=n₁(3R/2) + n₂(5R/2)

n₂/2=n₁/2

n₁/n₂=1

thanks

ans1) yes it is possible, only in one case ie when the two colliding bodies are of same mass and the collision is perfectly elastic in which one of the bodies is at rest intitally.Here the bodie initially in motion would come to rest after the collision and hence transfers all its KE to the other body.
ans) when a ball bounces of the floor , during the collision , ie, just befor and after the collision the time gap is very small.
according to the newtons second law
dp/dt=f
fdt is very small, dp is very small.
In this, dp means the change in momentum , which is very small or the momentum is constant/conserved.

The question dosen't make sense. If the distance between the centers of the spheres is greater than 2r and both are moving along parallel lines then how can they ever collide?

subs , that is what i'm saying, if the mass of the bead too much then the normal reaction would be very large and the maximum value of friction would be very large and hence the bead would not move.

the question here is not completel.

neeraj_agarwal_1990, there is something missing in your question the mass of the rod and the value of the coefficient of friction and the mass of the bead, the angular vel/acc .Such quantites have to be known or atleast there should exist some relation between them.

Eg, if the mass of the bead too large and the angular velocity of the rod is too small the bead may never slide because of the very low centrifugal force, check the question again .