question_answer

  Using second law of motion derive the relation between force and acceleration. A bullet of 10 g strikes a sand-bag at a speed of 103 m/s and gets embedded after travelling 5 cm. Calculate (i) the resistive force exerted by sand on the bullet (ii) the time taken by bullet to come to rest.

Answer:

                  Refer to text on page 217. Given m = 10 g = 0.01 kg, u = 103 m/s, v = 0, s = 5 cm = 0.05 m (i) (1) Force applied by the bullet F =ma = 0.01 x - 107   (Negative sign shows against the direction of motion)                                        (1) The resistive force exerted by the sand on the bullet (ii) Time taken by bullet to come to rest                                                                 (1)