Two arrows are fired horizontally with the same speed of 31.8 m/s. Each arrow has a mass of 0.149 kg. One is fired due east and the other due south. Find the magnitude of the total momentum of the two arrow system in kg-m/s. (Hint: How do you combine vector arrows at right angles?)

Answer 1

each vector has two components, most commonly in the x and y directions. So, you have

v = <31.8,0> + <0,-31.8> = <31.8,-31.8>

|v| = 31.8√2 = 44.97 m/s in a southeast direction, since tanθ = -31.8/31.8

so, the momentum p = mv