#18). (I think. It's the one that starts with "Compare..." Gravity ALWAYS attracts. The force between electric charges can attract or repel ... it depends whether the charges are the same kind or opposite kinds.
#19). With both gravity and electric charges, the force between them quickly becomes weaker when the distance between them increases.
#20). I don't think it changes. If the doorknob gets charged by something that TOUCHES it, so that charges can flow into it from the other object or out of it, then the total amount of electric charge on it might change. But the question says that the doorknob is charged by an "electric field", so nothing touched it, and charges couldn't flow into it or out of it. The only way it got charged was by the charges it already had in it getting moved around ... electrons in one part of the knob moving over to the other side. Then it would act as if it was charged ... if you touched it, you might get zapped.
#21)., #22)., #23). You're supposed to draw a graph to answer these. It's a very easy graph to draw, and you should do it. Label the x-axis 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. Label the y-axis 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2 . Put the four points on the graph ... A, B, C, and D. For each point, the 'battery voltage' is the number on the x-axis and the 'Current' is the number on the y-axis. Then draw a line through the points. When you have the graph to look at, you can easily answer 21, 22, and 23.
24). I'm not sure, and I don't want to guess.
25). Did you ever move a coil of wire near a magnet in class ? This is the same situation, only the magnet is moving and the wire is still. The result will be the same.
26). Magnets have two poles that attract the opposite kind and repel. Now you copy the map and fill in the other side.
This is a lot of work for 5 points, so I left some parts for you to do. Another reason I did that is: You'll learn a lot more that way.
A. magnetic field: prevents charged particles from the sun from reaching the surface
B. ozone: filters cancer-causing rays from the sun
C. carbon dioxide: retains heat energy from the sun in the atmosphere
D. water in oceans, lakes, rivers and streams: moderates changes in temperature on the surface
The electromagnetic field of the Earth protects us from solar wind by deflecting it. Without it, the charged particles would strip away our ozone, which will lead to the end of life on Earth.
The ozone is a layer in the stratosphere that filters the suns rays. It filters the UV rays by absorbing it. This prevents the UV rays from damaging the surface of the Earth.
Carbon dioxide retains heat in the atmosphere, which creates a greenhouse effect. It is beneficial for us, but because human activity like industrial activities emit so much carbon in the atmosphere that it ends up being harmful.
Bodies of water found on Earth regulate the temperature of the Earth through ocean currents. It brings in both cold and warm air to land which also affect precipitation.
Long explanation, I know, but maybe this will help you out in the long run. Good Luck!
In February 1784, just after the close of the Revolutionary War, the General Assembly of Georgia earmarked 40,000 acres of land to endow "a college or seminary of learning." The following year, Abraham Baldwin, a lawyer and minister educated at Yale University in New Haven, Connecticut, who had settled in Georgia