Answer:
[tex]v=1.043\times 10^{-9}\ m/s[/tex]
Explanation:
The expression for kinetic energy is:
[tex]K.E.=\frac {1}{2}\times m\times v^2[/tex]
K.E. is the kinetic energy = [tex]2.176\times 10^{-21}\ J[/tex]
m is the mass = 4 g = 0.004 kg (As 1 g = 0.001 kg)
v is the velocity
Applying values as:
[tex]2.176\times 10^{-21}=\frac{1}{2}\times 0.004\times v^2[/tex]
[tex]v^2=\frac{2.176\times 10^{-21}\times 2}{0.004}[/tex]
[tex]v=\sqrt{\frac{4.352}{10^{21}\times \:0.004}}[/tex]
[tex]v=1.043\times 10^{-9}\ m/s[/tex]
