Question

A 10 gm bullet is fired at the planck of wood with speed of 200 m per sec after passing through the planck is 1.0 m thick .the speed of bullet reduced to 10 m per sec find the average resisteanse

Answer 1

3rd equation of motion can be be applied: v^2 = u^2 + 2as, where acceleration is -ve. Hence v^2 = u^2 – 2as. v, final velocity = 0.

Therefore, u^2 = 2as. i.e. s is proportional to u^2. → s1÷ s2 = u1^2 ÷ u2^2.

Therefore, s2 = (u2^2 ÷ u1^2) x s1 = (200÷100)^2 x 2 (planks) = 8 planks. Answer is 8

Answer 2

♠♠♠Average Resistance = 8 ♠♠♪