Q.

When the position vector r→=xi^+yj^+zk^  changes sign as -r→ which one of the following vector will not flip under sign change   [2026]

1 Velocity  
2 Linear momentum  
3 Angular momentum  
4 Acceleration  

Ans.

(3)

r→=xi^+yj^+zk^

v→=dr→dt=vxi^+vyj^+vzk^

p→=mv→

L→=m(r→×v→)

    =(xi^+yj^+zk^)×m(vxi^+vyj^+vzk^)

When sign of r→ changes, L→ remains same.