Answer:
The correct answer is B
An echo underwater and an echo in the air will return at different times. The echo underwater will return more quickly than the echo in the air.
Explanation:
The physics of this is simple.
Water and air are both made up of particles. The particles for water are more closely or densely arranged that those of the air molecules. Hence sound travels faster in water than in air. When measured, the speed actually differs by as much as 5 times with water being the fastest medium.
Think of it like this. Assume you have two stacks of dominoes, one closely packed than the other but exactly the same amount of dominos, you'd notice that the stack that is more tightly arranged will be the first to topple over because it takes less time for the kinetic energy from the first domino to reach the next and on and on like that until the last domino.
Cheers
The same number of protons. brainliest?(:
Answer:
The driver's average velocity is 82.35 km/h.
Explanation:
Given:
The motion of the driver can be divided into 3 parts:
i. Displacement of the driver in 1.5 hours = 135 km
ii. Rest for 45 minutes.
iii. Displacement in next 2 hours = 215 km
The direction of motion remains same (east).
Now, total displacement of the driver is,
km.
Rest time is 45 minutes. Converting it to hours, we need to use the conversion factor
hour.
So, 45 minutes in hours is equal to
hours.
Now, total time taken for the complete journey is, 
Average velocity is given as:

Therefore, the driver's average velocity is 82.35 km/h
They gather data about the natural world.
hope that helped! :)
M1 = 750Kg, v1 = 10m/s
m2 = 2500Kg , v2= 0 (because in problem say cuz that object don t move).
The momentum before colision is equal with the momentum after colision:
m1v1 + m2v2 = (m1+m2)v3 => v3 is the velocity after colison and that s u want to caluclate for your problem
=> m1v1 = (m1+m2)v3 => v3 = m1v1/(m1+m2) now u should do the math i think v3 prox 2,4 but not sure u should caculate