If you doubled the mass and doubled the radius of a planet, by what factor would gg at its surface change

A6,600 kg train car moving at +2.0 m/s bumps into and locks together with one of mass 5,400kg moving at -3.0m/s. what is their final velocity? +0.50 m/s -1.0 m/s +2.5 m/s -0.25 m/s

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

Acaterpillar tries to climb straight up a wall a meter high, but for every 2 cm up it climbs, it slides down 1 cm. eventually, it reaches the top. when it reaches the top, it does not pull itself over so it will slide down 1 cm. what is the total displacement traveled?