Question Number 114158 by aurpeyz last updated on 17/Sep/20
Answered by aurpeyz last updated on 17/Sep/20
$${i}\:{am}\:{confused}\:{about}\:{the}\:{direction}\:{of}\:{the}\: \\ $$$${momentum}.\:{pls}\:{help} \\ $$
Answered by physicstutes last updated on 17/Sep/20
![Since p = mv , the direction of the velocity will be the same as the direction of the momentum. If we choose the right direction as positive then clearly after collision with the wall, the momentum will be negative. [if your figures are correct i.e the law of conservation of linear momentum hold].](Q114195.png)
$$\mathrm{Since}\:\boldsymbol{\mathrm{p}}\:=\:{m}\boldsymbol{\mathrm{v}}\:,\:\mathrm{the}\:\mathrm{direction}\:\mathrm{of}\:\mathrm{the}\:\mathrm{velocity}\:\mathrm{will}\:\mathrm{be}\:\mathrm{the}\:\mathrm{same} \\ $$$$\mathrm{as}\:\mathrm{the}\:\mathrm{direction}\:\mathrm{of}\:\mathrm{the}\:\mathrm{momentum}.\: \\ $$$$\mathrm{If}\:\mathrm{we}\:\mathrm{choose}\:\mathrm{the}\:\mathrm{right}\:\mathrm{direction}\:\mathrm{as}\:\mathrm{positive}\:\mathrm{then}\:\mathrm{clearly}\:\mathrm{after}\:\mathrm{collision}\: \\ $$$$\mathrm{with}\:\mathrm{the}\:\mathrm{wall},\:\mathrm{the}\:\mathrm{momentum}\:\mathrm{will}\:\mathrm{be}\:\mathrm{negative}.\:\left[\mathrm{if}\:\mathrm{your}\:\mathrm{figures}\right. \\ $$$$\left.\mathrm{are}\:\mathrm{correct}\:\mathrm{i}.\mathrm{e}\:\mathrm{the}\:\mathrm{law}\:\mathrm{of}\:\mathrm{conservation}\:\mathrm{of}\:\mathrm{linear}\:\mathrm{momentum}\:\mathrm{hold}\right]. \\ $$