Force in a magnetic field. Need help using the equation

AI Thread Summary
The discussion focuses on calculating the force per meter on a wire carrying a current in a magnetic field. For a 6.70-A current in a 0.89-T magnetic field at a 90-degree angle, the force is correctly calculated as 5.9 N/m. However, the user struggles with the calculation at a 45-degree angle, initially obtaining 5.07 N/m, which is incorrect. The key advice given is to ensure the calculator is set to degrees when using the sine function, as the sine of 45 degrees is crucial for the correct calculation. Understanding the relationship between degrees and radians is also emphasized for accurate results.
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Homework Statement



What is the magnitude of the force per meter of length on a straight wire carrying a 6.70-A current when perpendicular to a 0.89-T uniform magnetic field?

What if the angle between the wire and field is 45.0°?

I know how to do the whole thing, I just can't get my answer right. I don't know if I am working the equation out right.

Homework Equations



F=IlBsin\theta

The Attempt at a Solution



Using the above equation. For part A I know that I use it for 90 degrees at 1m

F=(6.70A)(0.89T)sin90=5.9N/m

Part B is the one I can't get the answer to.

F=(6.07A)(0.89T)sin45

**I haven't had a trig class or a physics class for about 7 years so I don't remember how to exactly use sin. For Part A I got the correct answer because I just didn't use the sin. I just took the (6.70A*0.89T). Can someone explain how to use sin or how to get the right answer. I got 5.07 N/m but that is not correct.

Thanks in advance to everyone that helps.
 
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It sounds like you had your calculator set to radians instead of degrees.

1 degree = pi/180 radians so 45 degrees= 45pi/180 =pi/4 radians

Try using that as your argument for sin.
 
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