Explain the greenhouse effect and how it affects the earth

At time t=0, a particle is located at the point (3,6,9). it travels in a straight line to the point (5,2,7), has speed 8 at (3,6,9) and constant acceleration 2i−4j−2k. find an equation for the position vector of the particle.

The heliocentric and the geocentric models of the solar system included these central principles

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply