a golf ball of mass 0.045kg is moving in the x-direction with a speed of 9.0 m/s, and a baseball with mass 0.145kg is moving in a negative y-directionwith a speed of 7m/s. what are the magnitude and direction of the total momentum of the system consisting of the two balls?

Answer 1

Using the standard orthogonal unit vectors î and ĵ.

Momentum of the system:
0.045*9.0 î - 0.145*7 ĵ kg∙m/s

Magnitude:
√((0.045*9.0)^2 + (0.145*7)^2) kg∙m/s

Direction: angle measured off x-axis
-arctan((0.145*7)/(0.045*9.0))