# Earth's magnetic force on a proton

• Jaccobtw
In summary, the conversation discusses a calculation involving the elementary charge, velocity, magnetic field, and angle. The calculated answer is questioned due to a lack of information about the strength of the magnetic field and the variability of the field on Earth's surface. The choice of 50 microtesla for the magnetic field is also questioned.
Jaccobtw
Homework Statement
A proton is flying to the east near the surface of the earth at 1000m/s. What is the magnitude of the force (in N) the proton feels due to the earth's magnetic field?
Relevant Equations
F = qvBsin##\theta##
Plug in the elementary charge for q, 1000 m/s for v, 50 microtesla for B and 90 degrees for theta and I get about 8e-21 Netwons. But apparently this is wrong, anyone know why? Thank you.

Your calculation looks correct. The problem statement as given doesn't provide the strength of the B-field. The field varies quite a bit over the surface of the earth. Why did you choose 50 μT?

TSny said:
Your calculation looks correct. The problem statement as given doesn't provide the strength of the B-field. The field varies quite a bit over the surface of the earth. Why did you choose 50 μT?

Jaccobtw said:
Click on the "varies quite a bit" in my previous post.

## 1. What is Earth's magnetic force on a proton?

Earth's magnetic force on a proton is the force exerted by Earth's magnetic field on a single proton. This force is caused by the interaction between the proton's electric charge and Earth's magnetic field.

## 2. How strong is Earth's magnetic force on a proton?

The strength of Earth's magnetic force on a proton varies depending on the location and orientation of the proton in relation to Earth's magnetic field. On average, it is approximately 2.5 x 10^-17 Newtons.

## 3. How does Earth's magnetic force on a proton affect its motion?

Earth's magnetic force on a proton causes it to experience a force perpendicular to its velocity, known as the Lorentz force. This force can cause the proton to change direction and follow a curved path.

## 4. Can Earth's magnetic force on a proton be shielded or blocked?

Yes, Earth's magnetic force on a proton can be shielded or blocked by materials that are highly permeable to magnetic fields, such as iron or steel. This is why compasses are affected by nearby metal objects.

## 5. How does Earth's magnetic force on a proton affect life on Earth?

Earth's magnetic force on a proton plays a crucial role in protecting life on Earth from harmful cosmic rays and solar winds. It also helps many animals, such as birds and sea turtles, navigate and orient themselves. Additionally, it is essential for the operation of many technological devices, such as compasses and MRI machines.

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