Question

13. A bullet hits a wall with a velocity of 20 m/s and
penetrates it up to a distance of 5 cm. Find the
deceleration of the bullet in the wall.​

Answer 1

GiveN :-

• Initial velocity of bullet = 20 m/s

• Final velocity of bullet = 0 m/s

• Distance travelled by bullet in wall = 5 cm = 5/100 m

To FinD :-

• Deceleration of the bullet

Solution :-

$\large\longrightarrow \boxed{ \bf \green{ {v}^{2} - {u}^{2} = 2as }}\\ \\\longrightarrow \sf {(0)}^{2} - {(20)}^{2} = 2 \times a \times \frac{5}{100} \\ \\\longrightarrow \sf - 400 = \frac{1}{10} a \\ \\\longrightarrow \sf a = - 400 \times 10 \\ \\\longrightarrow \sf a = - 4000 \: {ms}^{ - 2}$

$\therefore \: \underline{ \bf \blue{Deceleration \: of \: bullet \: is \:4000 \: {ms}^{ - 2} }}$