Kids love to crash their toy cars together.One such collision involves a 0.5 kg car moving at 0.3 m/s colliding with a stationary toy car of mass 0.3 kg.The two toys stick together and move away from the collision point at 0.188 m/s.By what factor is the initial kinetic energy greater than the final kinetic energy?

Question

Quizplus · Accepted Answer

The initial kinetic energy (KE_initial) can be calculated using the formula KE = 1/2 * m * v^2, where m is the mass and v is the velocity. For the moving car, KE_initial = 1/2 * 0.5 kg * (0.3 m/s)^2 = 0.0225 Joules. The stationary car has no initial kinetic energy.The final kinetic energy (KE_final) after the collision, when the cars stick together and move as one object, can be calculated using the combined mass (0.5 kg + 0.3 kg = 0.8 kg) and the final velocity (0.188 m/s). So, KE_final = 1/2 * 0.8 kg * (0.188 m/s)^2 = 0.01408 Joules.To find by what factor the initial kinetic energy is greater than the final kinetic energy, we divide the initial kinetic energy by the final kinetic energy: 0.0225 Joules / 0.01408 Joules ≈ 1.6.Therefore, the initial kinetic energy is 1.6 times greater than the final kinetic energy.

Kids Love to Crash Their Toy Cars Together