Question

please answer this. With full explanation.

Answer 1

Here it is given that if the radius of the earth is R than that of planet is 2R and mass of earth is M
And mass of planet is 8M right.

And we know
Escape velocity =(2GM/R) ½ or under root 2GM/R
And it is for earth right.

Now for planet
Escape velocity =(2G8M/2R)½
2 gets cancelled
We will left with 2(2GM/R)½

And we know (2GM /R) ½ is escape velocity on earth which is given to us as 11.2km/s

And here

Escape velocity of planet =2* escape velocity on earth

Escape velocity on planet =2*11.2=22.4km/s

Thanks for asking
Hope it will help