#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.
<span>When two point charges are a distance d apart, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be
changed to
When two point charges are a distance d apart, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be
changed to
d/âš2</span>
You can describe the<u> motion </u>of an object by saying it is moving in a straight line or is curved around another object. You can also describe where an object is by its <u> position </u> in relation to another object. The second object acts as a<u> reference</u> point. When an object changes position, you know it has motion. Motion can also be described by finding an object's <u>speed </u>or how fast or slow it moves in a certain amount of time. In addition, you can describe the object's speed AND direction together. This is called <u>velocity</u>
Explanation:
In the given answer-
<u>Motion</u> is defined as - the change in the movement or position of any object or body.
<u>Position</u> is said to be a place or somewhere or a location where any object or body is particularly placed/located or put on.
<u>Reference poin</u>t is a fixed point with regards to which any object or body changes its position. It is also called reference origin.
<u>Speed</u> is defined as the rate of any object covering certain distances. It is a scaler quantity (quantity which depends upon only magnitude).
<u>Velocity</u> is defined as the rate of speed per unit time. It is a vector quantity (quantity depending upon both magnitude and direction ).
