Answer:
Yes, it's correct
Explanation:
Newton's second Law states that the acceleration of an object is proportional to the net force applied on it, according to the equation:

where
F is the net force on the object
m is the mass of the object
a is the acceleration of the object
We can re-arrange the previous equation in order to solve explicitely for a, the acceleration, and we find:

So, we see that the acceleration is proportional to the net force and inversely proportional to the mass of the object.
The sound wave will have traveled 2565 m farther in water than in air.
Answer:
Explanation:
It is known that distance covered by any object is directly proportional to the velocity of the object and the time taken to cover that distance.
Distance = Velocity × Time.
So if time is kept constant, then the distance covered by a wave can vary depending on the velocity of the wave.
As we can see in the present case, the velocity of sound wave in air is 343 m/s. So in 2.25 s, the sound wave will be able to cover the distance as shown below.
Distance = 343 × 2.25 =771.75 m
And for the sound wave travelling in fresh water, the velocity is given as 1483 m/s. So in a time interval of 2.25 s, the distance can be determined as the product of velocity and time.
Distance = 1483×2.25=3337 m.
Since, the velocity of sound wave travelling in fresh water is greater than the sound wave travelling in air, the distance traveled by sound wave in fresh water will be greater.
Difference in distance covered in water and air = 3337-772 m = 2565 m
So the sound wave will have traveled 2565 m farther in water than in air.
watts = work per second.
work is mgh = 3x10x50=1500
watts out = 1500
Watts used = 2000
eff=1500/2000=75%