# physics

an electron with a speed of 5.00 x 10^8 cm/s enters an electric field of magnitude 1.00 x 10^3 N/C, traveling along field lines in the direction that s its motion.

a) How far will the electron travel in the field before stopping momentarily
b) how much time will have elapsed
c) in the region with the E field is only 8.00 mm long, what fraction of the electron's initial KE will be lost in that region?

1. 👍
2. 👎
3. 👁
1. F=ma
F=eE
ma = eE

a=eE/m= 1.6•10⁻¹⁹•10³/9.1•10⁻³¹= =1.76•10¹⁴ m/s²
s=v₀²/2a = v₀²m/2eE=
=(5•10⁶)²•9.1•10⁻³¹/2•1.6•10⁻¹⁹•10³= =0.071 m

v=v₀-at,
v=0,
t= v₀/a=5•10⁶/1.76•10¹⁴=2.84•10⁻ ⁸ s.

s₁=(v₀²-v₁²)/2a,
v₁² = v₀²-2s₁a.

KE₁/KE₀=(m v₁²/2)/ (m v₀²/2) =
= (v₁²/ v₀)² =( v₀²-2s₁a)/ v₀²=
=1-(2s₁a/ v₀²)= 1- (2•8•10⁻³•1.76•10¹⁴/25•10¹⁶)=
= 1-1.13•10⁻⁵=0.99999.

1. 👍
2. 👎

## Similar Questions

1. ### physics

An electron is released from rest in a uniform electric field and accelerates to the north at a rate of 115 m/s2. What are the magnitude and direction of the electric field.

2. ### physics

an electron enters the region of a uniform,electric field with 3X10^6m/s and e=200 N/C . the horizontal length of the plates is 0.100m. a) find the acceleration of the electron while it is in the electric field . b) if the

3. ### Physics

An electron is projected with an initial speed of (1.6x10^6 m/s) into the uniform field between two parallel plates. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside

4. ### physics

An electron is projected with an initial speed of (1.90x10^6 m/s) into the uniform field between two parallel plates. Assume that the field between the plates is uniform and directed vertically downward, and that the field outside

1. ### Physics

The figure below shows an electron passing between two charged metal plates that create an 115 N/C vertical electric field perpendicular to the electron’s original horizontal velocity. (These can be used to change the

2. ### Physics II

An electron with an initial speed of 5.0 ✕ 105 m/s enters a region in which there is an electric field directed along its direction of motion. If the electron travels 9.0 cm in the field before being stopped, what are the

3. ### physics

2) A proton is moving parallel to a uniform electric field. The electric field accelerates the proton and increases its linear momentum to 8.6 x 10^-23 kg·m/s from 2.4 x 10^-23 kg·m/s in a time of 5.7 x 10^-6 s. What is the

4. ### physics

An electron moving to the right at 4.0% the speed of light enters a uniform electric field parallel to its direction of motion. If the electron is to be brought to rest in the space of 5.0 cm, determine what the strength of the

1. ### physics help!

An electron enters the region of a uniform electric field between two oppositely charged parallel plates as shown, with an initial velocity of 3 x 106 m/s. The electric field between the plates is measured to be E = 200N/C. The

2. ### physics

Electronic types neglect the force of gravity on electrons.To see why, compute the force of Earth's gravity on an electron and compare it with the force exerted on the electron by an electric field of magnitude 6000 V/m (a

3. ### physics

An electron is moving through a magnetic field whose magnitude is 8.70*10^-4 T. The electron experiences only a magnetic force and has an acceleration of magnitude 3.50*10^14 m/s^2. At a certain instant, it has a speed of

4. ### Physics

Review Conceptual Example 2 as an aid in understanding this problem. A velocity selector has an electric field of magnitude 2607 N/C, directed vertically upward, and a horizontal magnetic field that is directed south. Charged