Can a body moving at 2m / s instantly change its speed to 4m / s?

Abird sitting high in a tree is an example of what type of wnergy

What’s #16 asking and how do i solve it?

The two stars in a certain binary star system move in circular orbits. the first star, alpha, has an orbital speed of 36 km/s. the second star, beta, has an orbital speed of 12 km/s. the orbital period is 137 d. a) what is the mass of the star alpha? b) what is the mass of the star beta?