Physics Homework question?
A 1.7 kg ball on the end of a lightweight rod is located at (x, y) = (4.0 m, 3.0 m), where the y-axis is vertical. The other end of the rod is attached to a pivot at (x, y) = (0 m, 4.0 m). What is the torque about the pivot? Express your answer using unit vectors. Best answer awarded
- JOHNLv 73 weeks agoFavorite Answer
Length of rod = √((4 – 0)² + ((3 – 4)²) = √17
i, j, k are unit vectors in the x-, y-, z-directions
Vector torque of ball about pivot is
(mgl)(-k) = 1.7 x 9.8 x √17 (-k) (using a right-handed
= - 68.7k Nm.