A Machine Gun Is Mounted On A Tank Moving At A Speed Of 20 Ms–1towards A Target With The Gun Pointing In The Direction Of Motion Of The Tank. The Muzzle Speed Of The Bullet Equals The Speed Of Sound = 340 Ms–1. If, At The Time Of Firing, The Target Is 500 M Away From The Tank, Then  

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A machine gun is mounted on a tank moving at a speed of 20 ms–1towards a target with the gun pointing in the direction of motion of the tank. The muzzle speed of the bullet equals the speed of sound = 340 ms–1. If, at the time of firing, the target is 500 m away from the tank, then  


Correct option is

The sound arrives at the target later than the bullet


Since only the source of sound, i.e. the gun is in motion, the speed of sound remains unchanged at 340 ms –1. Therefore, the time taken by the sound of firing to arrive at the target 500 m away is


If the gun points in the direction of motion of the tank, the effective speed of the bullet = 340 + 20 = 360 ms–1. Therefore the time taken by the bullet to reach the target is 


Since ts > tb.   




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