Posted by **Jess** on Tuesday, February 23, 2010 at 11:20pm.

We learned in lecture that the magnetic force on a charge q

moving with velocity v in a magnetic field ~B has the form

F = q~v × B

One important fact about the cross-product is that for two vectors A and B , the following is

true A × B = −B × A which may also be determined by using the right-hand-rule. A convenient

way to calculate a cross-product is to decompose the vectors involved into x,y and z components,

and then use the following basic cross-product results for the basis vectors,

ˆx × ˆy = ˆz , ˆy × ˆz = ˆx , ˆz × ˆx = ˆy

Using the result just stated, the cross-products in the opposite order produce a minus sign,

ˆy × ˆx = −ˆz , ˆz × ˆy = −ˆx , ˆx × ˆz = −ˆy

so one only needs to remember the first three identities above, and these other identities can be

easily remembered. For this problem, use these identities to calculate the magnetic force on a

particle with a charge q = 7μC in a magnetic field B = (5 × 10−5 T)ˆy. Do the calculation for the

following three different velocities:

(a) v = v0ˆx

(b) v = v0ˆy

(c) v = v0 (x+y/suare root 2) where v0 = 5m/s

## Answer this Question

## Related Questions

- physics - Which of the following is correct for the charge in a magnetic field...
- College physIcs - An electron travels at a speed of 4.0×104 m/s through a ...
- Physics 2 - List and explain briefly five magnetic devices found in the popular ...
- physics - The key ingredient in anything magnetic is which of the following?. A...
- Physics - An electron moving through a uniform magnetic field with a velocity of...
- Physics - An electron is moving paralel to the Earth's surface at the equator in...
- physics - Moving fast proton of 4x106 m / s through a 1.7 T magnetic field ...
- physics - A charge of -8.9 µC is traveling at a speed of 7.8 106 m/s in a ...
- physics - A particle with a charge of -4.0x10^-5 C, a mass of 2.0x10^-7 kg and a...
- physics - A particle with a charge of -4.0x10^-5 C, a mass of 2.0x10^-7 kg and a...

More Related Questions