Answer:
Explanation:
As the source is situated on x - axis , it must be situated in between the two listeners .
So the x coordinate of source is
(-7 + 3 )/2
= - 2 m
The equation of the wave- front will be that o a circle having centre at (-2,0)
and radius = distance between -2 and 3 , that is 5 m
equation of circle
=( x+2 )² + y² = 25
It cuts y axis when x = 0
Putting x = 0
4 + y² = 25
y² = 21
y = + √21 , or - √21
Kinetic energy per unit of mass is
Given, 
Therefore,
Now potential energy per unit mass is
Given, 
Therefore,
Thus, total mechanical energy of the river water per unit mass is
OR
Answer:
Explanation:
frequency of sound waves = 688 Hz
wavelength = 344 / 688 = .5 m
The problem is based on interference of sound waves
For the observer , path difference of sound waves reaching his ear
= 3.5 - 3.00
.5 m
= wavelength
Path difference is equal to wavelength so there will be constructive interference and hence louder sound will be heard by the listener than normal sound as sound waves interfere constructively.
Answer:
<em>58,800Joules</em>
Explanation:
The energy lost is equal to the workdone by the car as it skids.
Workdone = Force * Distance
Given
Force = 8000N
Get the distance using the equation of motion
v² = u² - 2gS
0² = 12² - 2(9.8)S
-12² = - 2(9.8)S
-144 = -19.6S
S = 144/19.6
S = 7.35m
Calculate the required energy
Workdone = 8000 * 7.35
Workdone = 58,800Joules
<em>Hence the energy lost due to friction is 58,800Joules</em>
