Elastic Collision Formula: An elastic collision is a type of collision between two objects in which both kinetic energy and momentum are conserved. In other words, when two objects collide elastically, they rebound off each other without any loss of kinetic energy. This is in contrast to inelastic collisions where kinetic energy is not conserved.
Also Check - Heat Input Formula
Conservation of Momentum:
m1 * u1_initial + m2 * u2_initial = m1 * v1_final + m2 * v2_finalConservation of Kinetic Energy:
0.5 * m1 * (u1_initial)^2 + 0.5 * m2 * (u2_initial)^2 = 0.5 * m1 * (v1_final)^2 + 0.5 * m2 * (v2_final)^2Also Check - Critical Velocity Formula
Given:
- m1 = 0.2 kg - u1_initial = 2 m/s - m2 = 0.3 kg - u2_initial = -1 m/s We need to find v1_final and v2_final Using these equations, you can calculate the final velocities of the two billiard balls.Also Check - Heat Of Vaporization Formula
Problem 2: Elastic Collision
Two cars, Car A and Car B, collide head-on. Car A has a mass of 1000 kg and is initially moving to the right at 20 m/s, while Car B has a mass of 800 kg and is initially moving to the left at 15 m/s. The collision between the two cars is perfectly elastic. Calculate the final velocities of Car A and Car B after the collision.Solution:
In an elastic collision, both momentum and kinetic energy are conserved. To find the final velocities of the two cars, we can use these principles. Step 1: Conservation of Momentum The total momentum before the collision is equal to the total momentum after the collision. Initial momentum of Car A = 1000 kg * 20 m/s = 20000 kg·m/s (to the right) Initial momentum of Car B = 800 kg * (-15 m/s) = -12000 kg·m/s (to the left) The total initial momentum = 20000 kg·m/s (to the right) - 12000 kg·m/s (to the left) = 8000 kg·m/s (to the right). The total momentum after the collision should also be 8000 kg·m/s to the right, as momentum is conserved.Also Check - Strain Formula
Step 2: Conservation of Kinetic Energy The total kinetic energy before the collision is equal to the total kinetic energy after the collision. Initial kinetic energy of Car A = 0.5 * 1000 kg * (20 m/s)^2 = 200,000 J Initial kinetic energy of Car B = 0.5 * 800 kg * (15 m/s)^2 = 90,000 J The total initial kinetic energy = 200,000 J + 90,000 J = 290,000 J. The total kinetic energy after the collision should also be 290,000 J, as kinetic energy is conserved. Now, we have the initial momentum and kinetic energy, and we know they are conserved after the collision. We can calculate the final velocities using the conserved values of momentum and kinetic energy. The final velocity of Car A = Total momentum / Mass of Car A Final velocity of Car A = 8000 kg·m/s / 1000 kg = 8 m/s to the right. The final velocity of Car B = Total momentum / Mass of Car B Final velocity of Car B = 8000 kg·m/s / 800 kg = 10 m/s to the right. So, the final velocity of Car A is 8 m/s to the right, and the final velocity of Car B is 10 m/s to the right. Both cars change direction and have their speeds adjusted in the direction of Car B's initial motion. For this problem, you can apply the same conservation of momentum and kinetic energy equations, but you have the advantage of knowing that the two balls have equal mass. Given that m1 = m2, and u1_initial = -u2_initial, you can simplify the equations and calculate their final velocities.