I love science! if you need any more help let me know i cant guarantee i can help but i will try!
The correct answer is "Some substances must be dissolved in water before they can be used".
Answer:
Explanation:
according to snell's law
refractive index of water n_w is 1.33
refractive index of glass n_g is 1.5
now applying snell's law between air and glass, so we have
![\beta = sin^{-1} [\frac{n_g}{n_a}*sin\alpha]](https://tex.z-dn.net/?f=%5Cbeta%20%3D%20sin%5E%7B-1%7D%20%5B%5Cfrac%7Bn_g%7D%7Bn_a%7D%2Asin%5Calpha%5D)
we know that
Answer:
The average velocity has magnitude = 10 km/h , direction: east
Explanation:
In order to find the average velocity of the car we need to know the final and initial positions, and the time that took to get from one to the other.
Notice that since its movement was 60 km straight east and then from there 40 km straight west, the car is positioned at 20 km to the east of its initial departure point. therefore the vector change in position is a vector 20 km in magnitude, and direction towards the east.
Since it took the car a total of 1.33 hours plus 0.67 hours to reach its final position, the total time elapsed is: 1.33 + 0.67 hours = 2 hours.
Then,the velocity vector has magnitude; 20 km / 2 hours = 10 km/hour
As we mentioned above. the direction of the velocity vector is east.
