A2.0 kg particle moves along an x axis, being propelled by a variable force directed along that axis. its position is given by , with x in meters and t in seconds. the factor c is a constant. at , the force on the particle has a magnitude of and is in the negative direction of the axis. what is c?

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?