A study of the Earth by The National Aeronautics and Space Administration (NASA) determined there were 6.20 ×10^11 tons of carbon stored in living plants on the Earth's surface, at the time of the study. Calculate the mass of carbon stored in these plants in grams. (1 ton equals 907.19 kg)

If the wheels lock when braking suddenly the vehicle: a: loses traction b: lose steering wheel ability c: gain speed slightly d: gain steering ability

Could someone me find the answer to this problem.

Four objects each with charge +2.0×10−7c are located at the corners of a square whose sides are 2.0 m long. part a what quantities can be determined using this information? check all that apply. the electric force on a charged object placed at the center of the square. the mass of each object. the total electric potential energy of the system consisting of the four charged objects. part b find the electric force on a charged object placed at the center of the square.