Middle school? lol but, the third one.
If you increase the frequency of a sound wave four times, t<span>he speed will increase four times. The correct option among all the options that are given in the question is the first option or option "A". This also shows the frequency and speed of the waves are directly proportional to each other. I hope it helps you.</span>
Explanation:
For air, n1 = 1.00003; for water, n2 = 1.3330
Given: θ2 = 30 degrees, then
θ1 = arcsin [(n2/n1) sin θ2]
= arcsin [(1.3330/1.0003) sin (40)]
= 58.93 degrees
Note that since, in this example, light is traveling from a medium of higher density (water; n2 = 1.3330) to a medium of lower density (air; n1 = 1.0003), then n2 > n1, and the angle of refraction (θ1) is larger than the angle of incidence (θ2), thus the light bends away from the normal (in this example, the vertical) as it leaves the water and enters the air.
Answer:
5. Solenoid B’s magnetic field is 2.7 times greater than solenoid A's magnetic field.
Explanation:
The magnetic field produced by a solenoid depends on number of coils, the length of the solenoid and the amount of current flowing through the coil.

Current in solenoid B is 2 times greater than the current in solenoid A.

Number of coils in B is 4 times greater than coils in A

Length of the solenoid B is 3 times greater than solenoid A


Thus, solenoid B's magnetic field is 2.7 times greater than magnetic field of solenoid A.
Answer:
v = 8.72 m/s
Explanation:
To find the speed of the raindrop joint to the mosquito, you take into account the momentum conservation law for an inelastic collision. Before the collision the total momentum of raindrop and mosquito must be equal to the total momentum of both raindrop and mosquito after the collision.
(1)
v1: speed of the mosquito before the collision= 0 m/s (it is at rest)
v2: speed of the raindrop before the collision = 8.9 m/s
m1: mass of the mosquito
m2: mass of the raindrop = 50m1 (50 time more massive that the mosquito)
v: speed of both raindrop and mosquito after the collision
You solve the equation (1) for v and replace the values of the rest of the parameters:

hence, after the inelastic collision the speed of the raindrop andmosquito is 8.72 m/s