Question

How long would it take for a sound impulse to travel through an aluminum rod 25 kilometers long? A. 0.0049 sec B. 0.071 sec C. 4.9 sec D. 0.14 sec

Answer 1

Answer: The answer is C. 4.9 sec.

Step-by-step explanation:

Answer 2

c) 4.9 s

Step-by-step explanation:

Young's modulus of aluminium is given as

`Y = 69 * 10^9 pa`

density of aluminium is given as

`\rho = 2700 kg/m^3`

now the speed of sound in aluminium is given as

`v = \sqrt{(Y)/(\rho)}`

`v = \sqrt{(69 * 10^9)/(2700)}`

`v = 5055.3 m/s`

now the time taken by the sound to travel a distance of d = 25 km

`t = (d)/(v)`

`t = (25 * 10^3)/(5055.3)`

`t = 4.9 s`