A bullet with a mass of 28g and travelling at 300m\s strikes a body with a mass of 14kg and which can move freely. The bullet remains in the body. At What velocity will the body start to move?
Use the fact that the total forward momentum is conserved.
0.028* 300 = 14.028* V
Solve for final velocity, V.
To find the velocity at which the body will start to move, we can use the principle of conservation of momentum.
The principle of conservation of momentum states that the total momentum before a collision is equal to the total momentum after the collision, provided no external forces are acting on the system.
In this case, we have a bullet with mass m₁ = 28g = 0.028kg and velocity v₁ = 300m/s. The body has mass m₂ = 14kg and initially has zero velocity.
The total momentum before the collision is given by:
Initial momentum = m₁ * v₁ + m₂ * v₂
After the collision, the bullet remains inside the body, so the mass of the body-bullet combination is the sum of their masses: m_total = m₁ + m₂. The bullet is at rest inside the body, so its final velocity is 0m/s.
The total momentum after the collision is given by:
Final momentum = m_total * v_final
According to the principle of conservation of momentum, the initial momentum is equal to the final momentum. Therefore, we can equate the two expressions:
m₁ * v₁ + m₂ * v₂ = m_total * v_final
Now we can solve for v_final, which is the velocity at which the body will start to move:
0.028kg * 300m/s + 14kg * 0m/s = (0.028kg + 14kg) * v_final
8.4kg·m/s = 14.028kg * v_final
Final velocity, v_final = 8.4kg·m/s / 14.028kg ≈ 0.599m/s
Therefore, the body will start to move with a velocity of approximately 0.599m/s.