The answer to question one is A.
The answer to question two is A.
The answer to question three is D.
Answer:
She covers the distance is 12 km.
The magnitude of displacement is 8.6 km.
The direction of her displacement is north east.
Explanation:
Given that,
Christina drives his moped 7 kilometers North and stop for lunch and then drive 5 km east.
We need to calculate the total distance
Using formula of distance
![d=d_{1}+d_{2}](https://tex.z-dn.net/?f=d%3Dd_%7B1%7D%2Bd_%7B2%7D)
Put the value into the formula
![d=7+5](https://tex.z-dn.net/?f=d%3D7%2B5)
![d=12\ km](https://tex.z-dn.net/?f=d%3D12%5C%20km)
We need to calculate the magnitude of displacement
Using formula of displacement
![D=xi+yj](https://tex.z-dn.net/?f=D%3Dxi%2Byj)
![D=5i+7j](https://tex.z-dn.net/?f=D%3D5i%2B7j)
![D=\sqrt{5^2+7^2}](https://tex.z-dn.net/?f=D%3D%5Csqrt%7B5%5E2%2B7%5E2%7D)
![D= 8.6\ km](https://tex.z-dn.net/?f=D%3D%208.6%5C%20km)
The direction of her displacement is north east.
Hence, She covers the distance is 12 km.
The magnitude of displacement is 8.6 km.
The direction of her displacement is north east.
Answer: 200 N/m
Explanation:
The Gravitational spring energy(Us) is equal to 1/2kx^2. So we have x as .2 m and Us as 4 N. So 4 N = 1/2 * k * .2^2. So now we solve for K and get 200 N/m.
Answer:
constructive interference in which waves strengthen each other
Explanation:
Some definitions:
- Costructive interference occurs when two (or more) waves meet each other in phase, so with same displacement at the same point. In such situation, the two waves strengthen each other, and the amplitude of the resultant wave is the sum of the amplitudes of the individual waves
- Destructive interference occurs when two waves meet each other in anti-phase, so with opposite displacement at the same point. In such situation, the two waves cancel each other out, and the amplitude of the resultant wave is the difference of the amplitudes of the individual waves (which means zero if the two waves are identical)
For light waves interfering with each other, 'white' means costructive interference, while 'black' means destructive interference (because black is absence of colors, so this means that the waves cancel each other out). In this problem, we see that point X, Y and X are white, therefore they are point of constructive interference, where the waves strengthen each other.