Question

When a mass is rotating in a plane about a fixed point, its angular momentum is directed along

• A. a line perpendicular to the plane of rotation
• B. the line making an angle of $45^{\circ}$ to the plane of rotation
• C. the radius
• D. the tangent to the orbit

Answer 1

Answer: (A)

a line perpendicular to the plane of rotation

Answer 2

When a mass is rotating in a plane about a fixed point its angular momentum is directed along a line perpendicular to the plane of rotation. $\vec{ L }=\vec{ r } \times mv$