Answer to Question #281766 in Physics for Nina

Question

A cheering squad is made up of three members: Lynne of 50kg moving at 3 m/sNorth. Angie of mass 58kg moving eastward at 3 m/s and Mercy of mass 6 kg moving at 3 m/s south. What is the combined momentum of the squad?

Answer 1

Find the combined momentum. The momentum has direction equal to the direction of velocity, the equation is $p=mv.$

$$p_L=50·3=150\text{ kg}·\text{m/s N}.\\ p_A=58·3=174\text{ kg}·\text{m/s E}.\\ p_M=60·3=180\text{ kg}·\text{m/s S}.\\ p_\text{North}=p_L-p_M=150-180=-30\text{ kg}·\text{m/s N}.\\ p_\text{East}=174\text{ kg}·\text{m/s N}.\\\space\\ p_\text{Combined}=\sqrt{p_\text{East}^2+p_\text{North}^2}=177\text{ kg}·\text{m/s N}.\\\space\\ \theta=\arctan\frac{p_\text{North}}{p_\text{East}}=9.8°\text{ S of E}.$$