If the person lets her arm swing freely from an initial position that is straight out and parallel to the ground, when is the angular acceleration of the arm about the shoulder the greatest?

Which branches of natural science include the study of an organism that lived 10 million years ago

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

Ahot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. a ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. ignore friction and air resistance and find the speed of the ball when it strikes the ground.