Question

Calculate the kinetic energy in j of an electron moving at 6.00 × 106 m/s. The mass of an electron is 9.11 × 10-28 g.

Answer 1

Answer:

• The kinetic energy in J of an electron moving at 6.00 × 10⁻⁶ m/s is:

         1.64 × 10 ⁻³⁸ J

Explanation:

1) Data:

a) KE =?

b) v =  6.00 × 10⁻⁶ m/s.

c) m = 9.11 × 10⁻²⁸ g.

2) Formula:

• KE = (1/2) mv²

3) Solution:

• KE = (1/2) =  (1/2) × 9.11 × 10⁻²⁸ g × ( 6.00 × 10⁻⁶ m/s)² = 163.98 × 10 ⁻⁴⁰ J

• KE = 1.64 × 10 ⁻³⁸ J

Answer 2

Answer: The kinetic energy of the electron is $1.64\times 10^{-17}J$

Explanation:

To calculate the kinetic energy of the electron, we use the equation:

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

where,

m = mass of the electron = $9.11\times 10^{-28}g=9.11\times 10^{-31}kg$   (Conversion factor:  1 kg = 1000 g)

v = speed of the electron = $6.00\times 10^6m/s$

Putting values in above equation, we get:

$E=\frac{1}{2}\times 9.11\times 10^{-31}kg\times (6.00\times 10^6m/s)^2\\\\E=1.64\times 10^{-17}J$

Hence, the kinetic energy of the electron is $1.64\times 10^{-17}J$