<span>The concept of plate tectonics regards the earth's CRUST as broken into a number of TECTONIC PLATES that are in motion relative to each other</span>

What is newton's second law of motion?Also give example.

<u>Definition</u>:-
Newton's Second Law of motion states that the rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of the force. ie., <u>F=ma</u>.
<u>Examples:-</u>
- When you are kicking a ball, you are increasing the speed by applying force to it. Therefore,it accelerates.
- If you use the same force to push a truck and push a car, the car will have more acceleration than the truck.
Derivation:-
For a body of mass 'm' , whose velocity changes from u to v in time t, when Force 'F' is applied.
=>Force∝Change in momentum/Time
=>F∝mv-mu/t
=>F∝m(v-u)/t
=>F∝ma
=>F=kma(a=v-u/t)
=>F=ma(Since k=constant=1)
Answer:
Impulse in the first collision is greater
Explanation:
u = Initial velocity of cart
v = Final velocity of cart
m = Mass of of cart
First collision
Impulse

Second collision
Impulse

Hence, the impulse in the first collision is greater than the second impact
Answer:
v=f×λ
Explanation:
v=f×λ
v is the speed of sound
f is the frequency of sound
λ is the wavelength
The speed of sound in air and water is different, but the frequency can be calculated from the given range above.
HAVE FUN LEARNING!!!( sorry im just to lazy to get the number so...)