A charge of -3.02 μC is fixed in place. From a horizontal distance of 0.0377 m, a particle of mass 9.43 x 10^-3 kg and charge -9.78 μC is fired with an initial speed of 80.4 m/s directly toward the fixed charge. How far does the particle travel before its speed is zero?

Respuesta :

Answer:

[tex]d = 0.0306 m[/tex]

Explanation:

Here we know that for the given system of charge we have no loss of energy as there is no friction force on it

So we will have

[tex]U + K = constant[/tex]

[tex]\frac{kq_1q_2}{r_1} + \frac{1}{2}mv_1^2 = \frac{kq_1q_2}{r_2} + \frac{1}{2}mv_2^2[/tex]

now we know when particle will reach the closest distance then due to electrostatic repulsion the speed will become zero.

So we have

[tex]\frac{(9 \times 10^9)(3.02 \mu C)(9.78 \mu C)}{0.0377} + \frac{1}{2}(9.43 \times 10^{-3})(80.4)^2 = \frac{(9 \times 10^9)(3.02 \mu C)(9.78 \mu C)}{r} + 0[/tex]

[tex]7.05 + 30.5 = \frac{0.266}{r}[/tex]

[tex]r = 7.08 \times 10^{-3} m[/tex]

so distance moved by the particle is given as

[tex]d = r_1 - r_2[/tex]

[tex]d = 0.0377 - 0.00708[/tex]

[tex]d = 0.0306 m[/tex]