According to einsteins explanation, what causes gravitation?

Determine the maximum r-value of the polar equation r =3+3 cos 0

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.