A car is stuck in the mud. Four adults each push on the back of the car with a force of 200N. What is the total force on the car?

In auto racing, a cruash occurs. A red car hits a blue car from the front with a force of 4000N. A yellow car also hits the blue car from the side with a force of 5000N. What is the total force on the blue car? (Since force is a vector, you must give both the magnitude and direction of the force.)

If the acceleration due to gravity at the surface of the Earth is approximately 9.8 m/s^2, what force does the gravitational attraction of the Earth exert on a 12.8-kg object?