Answer:
3.3m/s
Explanation:
You first get the total time (80 + 70 = 150s).
Then you would find the displacement of the truck. To do that you would do component method (vector addition), so since its a right triangle (North and East), displacement is 400^2 + 300^2 = d^2.
d= 500m.
So now that you have displacement and time, you can find the velocity:
v=d/t
v=500/150
v=3.3
Achieve a full outer shell
Answer:
-320 μJ.
Explanation:
Consider a point with an electrical charge of . Assume that is the electrical potential at the position of that charge. The electrical potential of that point charge will be equal to:
.
Keep in mind that since both and might not be positive, the size of the electrical potential energy might not be positive, either.
For this point charge,
- ; (that's -8.0 microjoules, which equals to )
- .
Hence its electrical potential energy:
.
Why is this value negative? The electrical potential energy of a charge is equal to the work needed to bring that charge from infinitely far away all the way to its current position. Also, negative charges are attracted towards regions of high electrical potential. Bringing this negative charge to the origin will not require any external work. Instead, this process will release 320 μJ of energy. As a result, the electrical potential energy is a negative value.
Well, the thing is: we don't really know, as we don't even know how many species there are on earth.
If we take a look at the estimates of <span>World Wide Fund for Nature, an organization that works toward combating species extinction, their estimates vary from 200 to 100 000 - but a probable number is 20 000 (d). </span>
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