Hey, I've been having trouble with the following question, and I've tried all I can think of and still can't get it. Your help is much appreciated. "A rocket with a total mass of 3700kg is traveling in outer space with a velocity of 110m/s towards the sun. It wishes to alter its course by 35.0 degrees, and can do this by firing its rockets briefly in direction perpendicular to its original motion. If the rocket gases are expelled at a speed of 1900m/s, how much gas mass must be expelled?" I already know the answer, its just a matter of getting to the answer that I have trouble with. A detailed explanation in other words.