What is the excess charge on the surface of the earth?

• gallib
In summary, the Earth has a vertical electric field at the surface, maintained by atmospheric processes, with an average magnitude of 117 N/C. The excess charge on the surface of the Earth can be calculated using the formula Q = Er^2/ke, where E is the electric field, r is the radius of the Earth, and ke is the permittivity constant. Alternatively, the net electric flux through the Earth's surface can be calculated using the formula E * 4pi*r^2 = excess charge / permittivity constant.
gallib

Homework Statement

The Earth has a vertical electric field at the surface, pointing down, that averages 117 N/C. This field is maintained by various atmospheric processes, including lightning. What is the excess charge on the surface of the earth?

Homework Equations

E=ke*Q/r^2 Q=Er^2/ke

The Attempt at a Solution

I attempted to plug in E = 117, r= radius of the earch, and ke= 8.99*10^9 into the equation to find Q, but this answer was wrong. Any ideas, thanks.

Why don't you use the formula for Electric flux? The Net electric flux through surface is basically Electric field * (4pi*(radius of Earth ^ 2)) = excess charge / permittivity constant.

Ah..thank you.

Last edited:
Yeah, permittivity constant is 8.85*10^-12.

What is the excess charge on the surface of the earth?

The excess charge on the surface of the earth is a result of the Earth's atmosphere being constantly bombarded by cosmic rays, which are high energy particles. These particles can either knock electrons off of atoms, resulting in a net positive charge, or add electrons to atoms, resulting in a net negative charge.

How is the excess charge on the surface of the earth measured?

The excess charge on the surface of the earth can be measured using a device called an electroscope. This instrument detects the presence of electric charge by measuring the repulsive forces between two charged objects.

What factors affect the amount of excess charge on the surface of the earth?

The amount of excess charge on the surface of the earth is affected by several factors, including solar activity, atmospheric conditions, and the Earth's own magnetic field. Solar activity, such as solar flares, can increase the amount of cosmic rays bombarding the atmosphere, resulting in a higher excess charge. Atmospheric conditions, such as thunderstorms, can also affect the amount of excess charge due to the buildup of static electricity. The Earth's magnetic field can also influence the amount of excess charge by deflecting some of the cosmic rays.

Can the excess charge on the surface of the earth be harmful?

The excess charge on the surface of the earth is generally not harmful to humans, as our bodies are able to conduct and dissipate this charge. However, in rare cases, the buildup of static electricity from the excess charge can lead to lightning strikes, which can be dangerous. It is important to take precautions during thunderstorms to avoid being struck by lightning.

What is being done to study and understand the excess charge on the surface of the earth?

Scientists and researchers are constantly studying the excess charge on the surface of the earth in order to better understand its effects and potential risks. This includes monitoring solar activity, measuring atmospheric conditions, and using advanced instruments to study the Earth's magnetic field. By gaining a better understanding of this phenomenon, we can better predict and prepare for potential hazards, such as lightning strikes.

• Introductory Physics Homework Help
Replies
35
Views
2K
• Introductory Physics Homework Help
Replies
23
Views
590
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
4
Views
560
• Introductory Physics Homework Help
Replies
11
Views
749
• Introductory Physics Homework Help
Replies
4
Views
295
• Introductory Physics Homework Help
Replies
1
Views
1K
• Introductory Physics Homework Help
Replies
21
Views
725
• Introductory Physics Homework Help
Replies
2
Views
816
• Introductory Physics Homework Help
Replies
5
Views
736