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A police jeep on a petrol duty on national highway was moving with a speed of 54km/hr. in the same direction. It finds a thief rushing up in a car at a rate of 126km/hr in the same direction. Police sub – inspector fired at the car of the thief with his service revolver with a muzzle speed of 100m/s. with what speed will the bullet hit the car of thief? |
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Answer» Answer: Speed of the police jeep = 54km/h Now we will convert the speed from kilometers to meters Speed of police jeep =54km/h 1km/hr =1000m/60x60sec=5/18 m/s = 54 x5/18 =270/18 =15m/s Therefore 54km./hr speed is EQUAL to 15m/s Speed of the police jeep = 54km/h=15m/s MUZZLE speed of the REVOLVER HIT by the police=100m/s Total velocity of the bullet= Speed of the car + muzzle speed= 100m/s + 15m/s= 115m/s Velocity of the thief’s car= 126km/h = 126x 5/18 = 35m/s Therefore 126km./hr speed is equal to 35m/s Velocity of the thief’s car=126km/h= 35m/s Relative velocity of the bullet with RESPECT to thief=Total velocity of the bullet – Velocity of the thief’s car= 115m/s – 35m/s= 80m/s So bullet will hit the car of the thief at a velocity 80 m/s |
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