A bullet of mass 10 g travelling horizon | Class 9 Science Chapter Force and Laws of Motion, Force and Laws of Motion NCERT Solutions

Question:

A bullet of mass 10 g travelling horizontally with a velocity of 150 m s-1 strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of the force exerted by the wooden block on the bullet.

Answer:

Mass of bullet, m = 10 g = 10 / 1000 = 0.01 kg

Initial velocity, u = 150 m/s

Final velocity, v = 0

Time taken, t = 0.03 s

Using the first equation of motion

 v = u + at

0 = 150 + (a ×0.03 s)

(Negative sign indicates that the velocity of the bullet is decreasing.)

Now, using the third equation of motion:

v2 = u2 + 2as

0 = (150)2 + 2 (−5000) s

Hence, the distance of penetration of the bullet is 2.25 m.

We know that

Force, F = Mass × Acceleration

F = ma = 0.01 × 5000 = 50 N

Hence, the magnitude of force is 50 N.


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Welcome to the NCERT Solutions for Class 9 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 3 , Question 14: A bullet of mass 10 g travelling horizontally with a velocity of 150 m s-1 strikes a stationary....