Conductors have many free electrons
insulators have few free electrons
conductors are ideal for electrical wiring
Answer:
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Speed = Distance/time
Speed = 800/40
Speed = 20 metre per second
part a)
Vector a has magnitude 12.3 and its direction is west, while Vector b has unknown magnitude and its direction is north. This means that the two vectors form a right-angle triangle, so a and b are two sides, while a+b is the hypothenuse.
We know the magnitude of a+b, which is 14.5, so we can use the Pythagorean theorem to calculate the magnitude of b:
part b) The direction of the vector a+b relative to west can be found by calculating the tangent of the angle of the right-angle triangle described in the previous part; the tangent of the angle is equal to the ratio between the opposite side (b) and the adjacent side (a):
And the angle is
with direction north-west.
part c)
This is exactly the same problem as the one we solved in part a): the only difference here is that the hypothenuse of the triangle is now given by a-b rather than a+b. In order to find a-b, we have to reverse the direction of b, which now points south. However, the calculations to get the magnitude of b are exactly the same as before, since the magnitude of (a-b) is the same as (a+b) (14.5 units), therefore the magnitude of b is still 7.68 units.
part d)
Again, this part is equivalent to part b); the only difference is that b points now south instead of north, so the vector (a-b) has direction south-west instead of north-west as before. Since the magnitude of the vectors involved are the same as part b), we still get the same angle, , but this time the direction is south-west instead of north-west.
Answer:
Explanation:
Given:
velocity of the sound,
time lag in echo form one wall of the valley,
time lag in echo form the other wall of the valley,
<u>distance travelled by the sound in the first case:</u>
Since this is the distance covered by the sound while going form the source to the walls and then coming back from the wall to the source so the distance of the wall form the source will be half of the distance obtained above.
<u>distance travelled by the sound in the second case:</u>
Since this is the distance covered by the sound while going form the source to the walls and then coming back from the wall to the source so the distance of the wall form the source will be half of the distance obtained above.
<u>Now the width of valley:</u>