A stream of $\alpha$-particles strikes a lead sheet. Every $\alpha$-particle in the stream has a mass of $6.6 \times 10^{-27}\ \text{kg}$ and a speed of $1.5 \times 10^{7}\ \text{m s}^{-1}$. $5.0 \times 10^{4}$ $\alpha$-particles per second strike an area of $1.0\ \text{cm}^{2}$ of lead. Nearly all of the $\alpha$-particles are absorbed by the lead, so their speed after collision is zero. What is an estimate of the average pressure exerted on the lead by the $\alpha$-particles?
- A$5.0 \times 10^{-15}\ \text{Pa}$
- B$5.0 \times 10^{-13}\ \text{Pa}$
- C$5.0 \times 10^{-11}\ \text{Pa}$
- D$5.0 \times 10^{-9}\ \text{Pa}$