# Biology Forums - Study Force

## Science-Related Homework Help Physics Topic started by: Zainab Ansari on Feb 1, 2023

 Title: AP Physics Potential Energy Post by: Zainab Ansari on Feb 1, 2023 3. Planet X-39 has a mass equal to 1/3 that of Earth and a radius equal to 1/3 that of Earth. If v is the escape speed for Earth, what is the escape speed for X-39? Title: Re: AP Physics Potential Energy Post by: bio_man on Feb 1, 2023 Escape velocity is the minimum velocity needed for an object to overcome the gravitational force exerted by the planet. It is given by the following relation :V = √(2GM/r)where,V - escape velocityG - gravitational constantM - mass of planetr - radius of planetWe can take the ratio of escape velocities as follow :V1/V2 = √(M1/M2) * √(r2/r1)where, 1 is for Earth and 2 is for X-39given that,V1 = VM2 = (1/3)*M1 => M1/M2 = 3r2 = (1/3)*r1 => r2/r1 = 1/3therefore,V/V2 = √3 * √(1/3) = 1ie. V2 = Vie. Escape velocity of X-39 is same as that of Earth. Title: Re: AP Physics Potential Energy Post by: bio_man on Feb 1, 2023 The escape speed for a planet is determined by its mass and radius, and it can be calculated using the formula:v = √(2GM/R)where G is the gravitational constant, M is the mass of the planet, and R is its radius.Since X-39 has a mass equal to 1/3 that of Earth and a radius equal to 1/3 that of Earth, the escape speed for X-39 can be calculated as follows:v = √(2G * (1/3M) / (1/3R)) = √(2G * M / R) / √(1/3) = √(2GM/R) / √(1/3) = v / √(1/3)So the escape speed for X-39 is 1/√(3) times the escape speed for Earth.