In a television tube, an electron (mass 9.1 * 10^-31 kg) starting from rest experiences a force of 4.8 *10^-15N over a distance of 45 cm. Ignoring relativistic effects, the final speed of the electron is

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The final speed of the electron can be found using the work-energy principle. The work done on the electron by the force is equal to the change in kinetic energy. Work is calculated as force times distance (W = Fd). Given that the force (F) is $4.8 \times 10^{-15}$ N and the distance (d) is 0.45 m (45 cm), the work done is $W = 4.8 \times 10^{-15} \times 0.45$. The change in kinetic energy ($\Delta KE$) is equal to this work, and since the electron starts from rest, $\Delta KE = \frac{1}{2}mv^2$, where $m$ is the mass of the electron ($9.1 \times 10^{-31}$ kg) and $v$ is the final velocity. Solving for $v$ gives the final speed of the electron, which matches the value in choice C.

In a Television Tube, an Electron (Mass 9