In the figure, a proton is fired with an initial speed (v_o) of 150,000 m/s from

Question

In the figure, a proton is fired with an initial speed (v_o) of 150,000 m/s from the midpoint of the capacitor toward the positive plate as shown. The plates are 10 cm. apart. Find the location where the proton stops and turns around (use x = 0 as the location of the negative plate) ______ What is the potential at that location? ______ What is the proton's speed when it reaches the 100V location? _____ If an electron is fired from the positive plate with an initial velocity that is 80 times faster than the initial velocity of the proton, how far from the 0V plate will it stop? _______ In the figure to the right: What is the escape speed of the proton (middle charge)? (Assume the two outer charges are fixed in 5 mm place) _______ If the proton (middle charge) is launch with half of the escape speed, how far away from its starting point will it stop and turn around? ______ An electric dipole consists of 1.0 g spheres charged to plusminus 3.0nC at the ends of a 15 cm long non-conducting rod of mass 4g. The dipole rotates on a frictionless pivot at its center. The dipole is held perpendicular to a uniform electric field with a field strength 1000 V/m, then released. What is the dipole's angular velocity at the instant it is aligned with the electric field?

Explanation / Answer

a)

i) Conserving energy

Since proton starts from middle = 250V potential

now

When it stops

KE => PE

0.5mv^2 = qV

substituting

we get V= 117.28 V

Hence proton reaches a location of 250+117.28 = 367.28 V = 367.28*10/500 = 7.346 cm

now

ii) Potential at that position = 367.28V

iii) Now

When it reaches 100V position

dV = 367.28-100 = 267.28 V

Hence

Using same relation

v = 226449.44 m/s

iv) Now

Using

0.5*9.11*10^-31*(80*150000)^2 = 1.602*10^-19V

V = 409.44 V = 409.44*10/500 = 8.19

Hence it reaches 10-8.19 = 1.81 cm far from the negative plate

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.