A solar airplane is going from Earth to Mars. Its sail is oriented to give a solar radiation force of 8.00x10^2 N. The gravitational force due to the Sun is 173 N and the gravitational force due to the Earth is 1.00x10^2 N. All forces are in the plane formed by Earth, Sun, and sailplane. The mass of the sailplane is 14,500 kg. What is the net force (magnitude and direction) acting on the sailplane? We NEVER covered this in class and I am thoroughly stumped. I've been searching everywhere for a potential solution. I REALLY hope someone can help me here. I honestly have no clue. All I can think of is adding all the forces and multiplying it by the mass. Please help!