red hot is hot, but other colours are even hotter. stars may be hotter than red hot.
there is also something calle the red shift.
What a relief ! That gives her time to step out of the way, before the ball
comes crashing down in the same place where she was standing.
Answer:
The workdone is 
Explanation:
From the question we are told that
The height of the cylinder is 
The face Area is 
The density of the cylinder is 
Where
is the density of freshwater which has a constant value

Now
Let the final height of the device under the water be 
Let the initial volume underwater be 
Let the initial height under water be 
Let the final volume under water be 
According to the rule of floatation
The weight of the cylinder = Upward thrust
This is mathematically represented as


So 
=> 
Now the work done is mathematically represented as

![= \rho_w g A [\frac{h^2}{2} ] \left | h_f} \atop {h}} \right.](https://tex.z-dn.net/?f=%3D%20%20%20%5Crho_w%20g%20A%20%5B%5Cfrac%7Bh%5E2%7D%7B2%7D%20%5D%20%5Cleft%20%7C%20h_f%7D%20%5Catop%20%7Bh%7D%7D%20%5Cright.)
![= \frac{g A \rho}{2} [h^2 - h_f^2]](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7Bg%20A%20%5Crho%7D%7B2%7D%20%20%5Bh%5E2%20-%20h_f%5E2%5D)
![= \frac{g A \rho}{2} (h^2) [1 - \frac{h_f^2}{h^2} ]](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7Bg%20A%20%5Crho%7D%7B2%7D%20%28h%5E2%29%20%20%5B1%20%20-%20%5Cfrac%7Bh_f%5E2%7D%7Bh%5E2%7D%20%5D)
Substituting values

Answer:
Explanation:
The angular momentum of electron mvR = 6 x 10⁻²⁵ Js
Magnetic field B = 2.5 x 10⁻³ T
radius of circular path R = mv / Bq
where m is mass , v is velocity and q is charge on electron
R² = mvR / Bq
R² = 6 x 10⁻²⁵ / 2.5 x 10⁻³ x 1.6 x 10⁻¹⁹
= 1.5 x 10⁻³
R = 3.87 x 10⁻² m
mvR = 6 x 10⁻²⁵
v = 6 x 10⁻²⁵ / mR
= 6 x 10⁻²⁵ / 9.1 x 10⁻³¹ x 3.87 x 10⁻²
= .17 x 10⁸
= 17 x 10⁶ m/s