The momentum of a moving particle is vectorially given a, `vecp=p_(0)(costhati+sinthatj)`where `t` stands for time. Choose the correct option:

Options

A. The applied force is constant.
B. The momentum is constant.
C. The applied force always remains perpendicular to the momentum.
D. The applied force is always parallel to the momentum.

Answer

C

Explanation

`p=p_(0)(costhati+sinthatj)`
`vecF=(vec(dp))/(dt)=p_(0)[-sinthati+costhatj]`
Both`vecp` and `vecF` are function of time. So none of the is constant.
We see that `vecF.vecp=0`, so `vecF_|_^(r)vecp`