At the equator, the earth\'s magnetic field is approximately horizontal and is d

Question

At the equator, the earth's magnetic field is approximately horizontal and is directed toward the north and has a value of 8*10^(-5) T. A)Estimate the emf induced between the top and bottom of a bullet shot horizontally at a target on the equator if the bullet is shot toward the east. Assume the bullet has a length of 1 cm and a diameter of 0.4cm and is traveling at 340 m/s. B) Which is at higher potential, the top or bottom of the bullet? C) What is the emf if the bullet travels south? D)What is the emf induced between the front and back of the bullet for any horizontal velocity?

Explanation / Answer

Let a small test charge q rest within the bullet. The force on this charge, which is qE + qv×B, is zero. To counteract the force on the test charge due to the qv×B term, which will be upward for a positive test charge, the electrical field must be uniformly downward. The voltage between the topmost and bottom most part of the bullet is therefore Ed, where d is the diameter of the bullet, the top of the bullet being positive. Because E = vB, the voltage V will be V = Ed = vBd = 340 m/s * 8e-5 T * 4e-3 m = 0.1088 millivolts The length of the bullet doesn't enter into the calculation. This is also in addition to the speed of the bullet resulting from the earth's rotation, which is roughly comparable in magnitude to the bullet's muzzle velocity.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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