Consider a planet with twice the mass and twice the radius of earth. its escape speed is how many times that of earth?
a. 0.25
b. 0.5
c. 1
d. 2
e. 4

1

Explanation:

The escape speed of the earth is given by here G is gravitational constant and M is the mass and R is the radius of the earth

Now in the question it is said that if mass is increases twice and radius is also becomes twice so escape speed it is the same before the changing the mass and radius of the earth so the escape speed will be same that is 1 times of the earth

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m