A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further it will penetrate before coming to rest, assuming that it faces constant resistance to motion?
AIEEE Solved Paper-2005
A)3.0 cm
B) 2.0 cm
C) 1.5 cm
D) 1.0 cm
Correct Answer:
D
Solution :
According to work-energy theorem, Case I When bullet is penetrating 3 cm where, F is resistive force andis initial speed. Case II Let the further distance travelled by the bullet before coming to rest is s. \[-F(3+s)\,={{K}_{f}}-{{K}_{i}}=-\frac{1}{2}\,mv_{0}^{2}\] or or or