04:45
University Physics with Modern Physics
A particle with a charge of $-1.24 \times 10^{-8} \mathrm{C}$ is moving with instantaneous velocity $\vec{v}=\left(4.19 \times 10^{4} \mathrm{m} / \mathrm{s}\right) \hat{\imath}+(-3.85 \times$ $10^{4} \mathrm{m} / \mathrm{s} ) \hat{\boldsymbol{J}}$ . What is the force exerted on this particle by a mag-
netic field (a) $\vec{\boldsymbol{B}}=(1.40 \mathrm{T}) \hat{\boldsymbol{i}}$ and $(\mathrm{b}) \vec{\boldsymbol{B}}=(1.40 \mathrm{T}) \hat{\boldsymbol{k}} ?$