You have arrived at a new planet and put your starship into a circular orbit at a height above the surface that is equal to two times the radius of the planet. Your speed is 4300 m/s and it takes 7 hours and 18 minutes to complete an orbit.

a. What is the radius of the planet?

b. What is the mass of the planet?

a. Let R be the radius of the orbit and R' be the radius of the planet.

V *7.3 min*60 sec/min = 2*pi*R
Solve for R, then use R' = R/2.

b. G*M/R^2 = V^2/R
Solve for M

for the second equation use R, not R' correct?

To find the radius of the planet, we can use the information about the orbit height and the orbital period.

a. The height above the surface is equal to two times the radius of the planet. Let's denote the radius as 'r'. So the height is 2r.

b. The orbital period is the time it takes for the starship to complete one full orbit. In this case, it is given as 7 hours and 18 minutes, which can be converted to hours. 7 hours + (18 minutes / 60 minutes per hour) = 7.3 hours.

To solve for the radius, we can use the formula for the orbital period (T) of a circular orbit:

T = 2π * √(r^3 / GM)

Where G is the gravitational constant and M is the mass of the planet.

We can rearrange the formula to solve for the radius (r):

T^2 = (4π^2 / GM) * r^3

Now, let's plug in the known values:

T = 7.3 hours = 7.3 * 60 * 60 seconds (convert hours to seconds)
T = 26,280 seconds

Solving for the radius (r):

r^3 = (GM / (4π^2)) * T^2

r^3 = (G / (4π^2)) * (M * T^2)

r = ( (G / (4π^2)) * (M * T^2) )^(1/3)

Now, we can estimate the radius of the planet.