What are the units for gravitational field strength ?

Are aliens real? justify you’re answer.

Aparticle travels in a circular orbit of radius 21 m. its speed is changing at a rate of 23.1 m/s2 at an instant when its speed is 37.2 m/s. what is the magnitude of the acceleration (in m/s? ) of the particle?

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