#### Answer

$-5.51 \times 10^{-19} J$.

#### Work Step by Step

The work done on the electron is the change in its kinetic energy, by equation 6–4. The final KE is zero.
$$W = \Delta KE = 0-\frac{1}{2} mv^{2}$$
$$W = -\frac{1}{2} (9.11 \times 10^{-31}kg)(1.10 \times 10^6 m/s)^{2}=-5.51 \times 10^{-19} J$$
The work is negative because the electron slows down.