a proton travelling along is x-axis is lowed by a niform electric field E. at x = 20.0 cm, the proton has a speed of 3.5x10^6 m/s and at 80.0 cm the speed is zero. Determine the magnitude and direction of e,

Respuesta :

Answer:

Magnitude of electric field is 1.06 x [tex]10^5[/tex] V/m along negative X-direction

Explanation:

Given: initial velocity of proton = u = 3.5 x [tex]10^6[/tex] m/s

final velocity of proton = v = 0 m/s

initial point [tex]l_i[/tex] = 0.2 m and final point is [tex]l_f[/tex] = 0.8 m

According to conservation of energy:

change in in kinetic energy = change in potential energy of proton

⇒[tex]\frac{m}{2}(v^2-u^2 ) = qE(l_i - l_f)[/tex]

where q and m is the charge and mass of proton E is the electric field , [tex]l_i[/tex] and [tex]l_f[/tex] is the initial and final position of proton

on substituting the respected values we get,

1.023 x [tex]10^-^1^4[/tex] = 9.6 x [tex]10^-^2^0[/tex] x E

E = 1.06 x [tex]10^5[/tex] V/m

external force is opposite to the motion as velocity of proton decreases with distance.

Therefore, magnitude of electric field is 1.06 x [tex]10^5[/tex] V/m along negative X-direction