Force Questions

A very long straight wire carries a current I. At the instant when a charge + Q at point P has velocity , as shown, the force on the charge is :

A body, under the action of a force $\vec{F}=6\hat{i}-8\hat{j}+10\hat{k}$, acquires an acceleration of $1{\text{m/s}}^2$. The mass of this body must be: