A proton moves with velocity v = 3 × 10⁶ i m/s in a magnetic field B = 0.5 k T — JEE Physics
A proton moves with velocity $\vec{v} = 3 \times 10^6\ \hat{i}$ m/s in a magnetic field $\vec{B} = 0.5\ \hat{k}$ T. Find the magnetic force on it. ($e = 1.6 \times 10^{-19}$ C)
1 Answer
$$\vec{F} = q(\vec{v} \times \vec{B}) = 1.6\times10^{-19}(3\times10^6 \hat{i} \times 0.5\hat{k})$$
$$\hat{i} \times \hat{k} = -\hat{j}$$
$$\vec{F} = 1.6\times10^{-19} \times 1.5\times10^6 (-\hat{j}) = -2.4\times10^{-13}\ \hat{j} N$$