To solve this problem, we can use the principle of conservation of momentum. The momentum of an object is given by the product of its mass and velocity. If we assume that the mass of the bullet remains constant throughout its penetration, we can equate the initial momentum to the final momentum.
Let's denote the velocity of the bullet after penetrating the wooden planks as v.
Given: Initial velocity of the bullet (u) = 10 m/s Number of wooden planks penetrated = 10
The initial momentum (P₁) of the bullet can be calculated as: P₁ = mass × initial velocity
Now, according to the principle of conservation of momentum: P₁ = P₂
The final momentum (P₂) of the bullet can be calculated as: P₂ = mass × final velocity
Since the mass remains constant, we can write: mass × initial velocity = mass × final velocity
Canceling out the mass from both sides of the equation, we have: initial velocity = final velocity
Therefore, the velocity of the bullet after penetrating the wooden planks is 10 m/s.