Answer:
Explanation:
Given
Distance between two loud speakers 
Distance of person from one speaker 
Distance of person from second speaker 
Path difference between the waves is given by

for destructive interference m=0 I.e.




frequency is given by

where 

For next frequency which will cause destructive interference is
i.e.
and 


frequency corresponding to this is

for 


Frequency corresponding to this wavelength

In order to delete a file, it is required to first select the file which you want to delete and then select 'delete' from the file menu. It will then ask you to confirm the deletion which will be required in order to complete the file deletion process.
It isn't required to click on the X at the top right of the screen or to open the file you want to delete as these steps aren't relevant to the deletion process.
Hence, the statements which describe the steps you need to take in order to delete a file are as follows:
- Confirm the deletion.
- Select Delete from the File menu.
- Select the file you want to delete.
Answer:
Rate of heat is 45.1 kJ/min
Explanation:
Heat required to evaporate the water is given by
Q = mL
here we know that

now we have


now the power is defined as rate of energy



Answer:
Explanation 118 = (1/2) * 0.15 * v² 118 = 0.075 * v² v² = 1573.33 m/s ... since KE = m/2*V^2 , then : V = √2KE/m = √20*118/1.5 = 39.67 m//sec ( 142.8 km/h ; 88.75 mph).: