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CBSE Class 9 Answered

A bullet of mass 30 g loses 80% of its velocity when it comes out from a sand bag within 0.3 seconds. If its initial velocity of penetration is 25 m/s, the nagnitude of resistive force acting on it is:
Asked by Amithjose | 19 Oct, 2012, 10:11: PM
answered-by-expert Expert Answer
initial velocity = 25 m/s
final velocity = 80/100 * 25 = 20 m/s
 
thus acceleration = (20 - 25)/0.3 = - 50/3 m/s/s
thus force = 0.03 * 50/3 = 0.5 N of resistive force
Answered by | 19 Oct, 2012, 10:44: PM

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