Final answer:
To calculate the speed of an electron with a kinetic energy of 4.5e⁻¹⁸ J, we use the formula KE = ½mv². Considering the mass of an electron (9.11 × 10⁻³¹ kg), the speed is computed, which is significant but non-relativistic.
Step-by-step explanation:
The question asks us to calculate the speed of an electron given its kinetic energy of 4.5e⁻¹⁸ joules. To find the speed of the electron, we can use the classical kinetic energy formula KE = ½mv², where KE is kinetic energy, m is the mass of the electron, and v is the velocity of the electron. The mass of an electron is 9.11 × 10⁻³¹ kg. Rearranging the kinetic energy formula to solve for speed, we get v = √(2KE/m).
Plugging in the values:
v = √(2 × 4.5e⁻¹⁸ J / (9.11 × 10⁻³¹ kg))
We calculate the speed v and find that, although significant, it's not close to relativistic speeds like 0.914c where relativistic effects need to be considered, as the kinetic energy is not 150% of the rest mass energy of an electron, which is 0.511 MeV.