Gravity can be described as (2 points) an magnetic force found in nature. the force that moves electrical charges. the force that repels object with like charges. the force of attraction between two objects

What is a view of science and psychology that says the value of knowledge depends on its usefulness? a. pragmatism b. psychotherapy c. physiology

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

How many astronauts have walked on the moon?