<h2>
Answer:</h2>
<em><u>(a). 16.741 m/s</u></em>
<em><u>(b). 15.75 m/s</u></em>
<h2>
Explanation:</h2>
In the question,
Height of the cliff, h = 37 m
Time taken to reach the sound to us = 2.92 s
Speed of the sound in air at room temperature = 343 m/s
Now,
Let us say the speed of the ball = u m/s
So,
Time taken by the ball to reach at the bottom, t is given by,
![t=\sqrt{\frac{2h}{g}}\\t=\sqrt{\frac{2\times 37}{9.8}}\\t=2.747\,s](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B%5Cfrac%7B2h%7D%7Bg%7D%7D%5C%5Ct%3D%5Csqrt%7B%5Cfrac%7B2%5Ctimes%2037%7D%7B9.8%7D%7D%5C%5Ct%3D2.747%5C%2Cs)
So,
Splash is heard after = 2.92 s
So,
<u>Time taken by sound to travel the shortest distance along the hypotenuse of the triangle</u> thus formed is,
t = 2.92 - 2.747
t = 0.172 s
Now,
Distance traveled by sound is given by,
![Distance=343\times 0.172\\Distance=59.02\,m](https://tex.z-dn.net/?f=Distance%3D343%5Ctimes%200.172%5C%5CDistance%3D59.02%5C%2Cm)
So,
In the triangle using the Pythagoras Theorem,
Horizontal distance traveled is,
![D=\sqrt{59.02^{2}-37^{2}}\\D=45.99\,m](https://tex.z-dn.net/?f=D%3D%5Csqrt%7B59.02%5E%7B2%7D-37%5E%7B2%7D%7D%5C%5CD%3D45.99%5C%2Cm)
So,
Speed of throwing of ball is given by,
![Distance=Speed\times Time\\45.99=u\times 2.747\\u=16.741\,m/s](https://tex.z-dn.net/?f=Distance%3DSpeed%5Ctimes%20Time%5C%5C45.99%3Du%5Ctimes%202.747%5C%5Cu%3D16.741%5C%2Cm%2Fs)
<em><u>Therefore, the speed of the ball = 16.741 m/s.</u></em>
(b).
If,
Speed of sound = 331 m/s
So,
<u>Distance traveled by sound</u> is,
![Distance=331\times 0.172\\Distance=56.932\,m](https://tex.z-dn.net/?f=Distance%3D331%5Ctimes%200.172%5C%5CDistance%3D56.932%5C%2Cm)
So,
Distance traveled in the horizontal by ball is,
![Distance=\sqrt{56.932^{2}-37^{2}}\\Distance=43.269\,m](https://tex.z-dn.net/?f=Distance%3D%5Csqrt%7B56.932%5E%7B2%7D-37%5E%7B2%7D%7D%5C%5CDistance%3D43.269%5C%2Cm)
So,
Speed of the ball thrown is given by,
![Speed=\frac{Distance}{Time}\\Speed=\frac{43.269}{2.747}\\Speed=15.75\,m/s](https://tex.z-dn.net/?f=Speed%3D%5Cfrac%7BDistance%7D%7BTime%7D%5C%5CSpeed%3D%5Cfrac%7B43.269%7D%7B2.747%7D%5C%5CSpeed%3D15.75%5C%2Cm%2Fs)
<em><u>Therefore, the speed of the ball = 15.75 m/s.</u></em>