Question

In each part calculate the kinetic energy of the given objects in joules c) an electron (mass 9.11x10^-31kg) moving at a speed of 2.74x10^7m/s

Answer 1

The kinetic energy of an object with mass m that moves with speed v is given by:

$K=\frac{1}{2}mv^2$

Plugging the mass and speed given in the equation above we have that:

$\begin{gathered} K=\frac{1}{2}(9.11\times10^{31})(2.74\times10^7)^2 \\ K=3.42\times10^{-16} \end{gathered}$

Therefore, the kinetic energy of the electron is:

$3.42\times10^{-16}\text{ J}$