## THIS USER ASKED ðŸ‘‡

**What is the kinetic energy K of an electron with momentum 1.05Ã—10âˆ’24 kilogram meters per second?Express your answer in electron volts to two significant figures.**

## THIS IS THE BEST ANSWER ðŸ‘‡

Momentum = mv elsewhere the mass of an electron and v is the velocity of the electron.

v = momentum Ã· m = (1.05 Ã— 10âˆ§-24) Ã· (9.1 Ã— 10âˆ§-31) = 1,153,846.154 m / s

kinetic energy = (mvâˆ§2) Ã· 2 = (9.1 Ã— 10âˆ§-31 Ã— 1,153,846.154âˆ§2) Ã· 2 = (1.21154 Ã— 10âˆ§-18) Ã· 2 = 6.05769 Ã— 10âˆ§-19 J

Thus, 3.8eV from 1J = 6. 242 Ã— 10 ^ 18