Question

Car A has a mass of 1000kg moving at a velocity of 20m/s collides with Car B of mass 1200kkg moving at 10m/s in the same directionIf the car B is shunted forward at 15m/s by the impact, what is the velocity,v, of the car A immediately after the crash?

Answer 1

Answer on Question 57177, Physics, Mechanics, Relativity

Question:

Car A has a mass of $1000\,kg$ moving at a velocity of $20\,m/s$ collides with car B of mass $1200\,kg$ moving at $10\,m/s$ in the same direction. If the car B is shunted forward at $15\,m/s$ by the impact, what is the velocity, $v_{Af}$, of the car A immediately after the crash?

Solution:

Let’s assume that both cars move in the same positive direction $x$. Then, we can apply the law of conservation of momentum:

$$m_A v_{Ai} + m_B v_{Bi} = m_A v_{Af} + m_B v_{Bf},$$

here, $m_A$, $m_B$ is the mass of the cars, $v_{Ai}$, $v_{Bi}$ is its velocities before collision and $v_{Af}$, $v_{Bf}$ is its velocities after collision.

From this equation we can find the velocity of the car A immediately after the crash:

$$v_{Af} = \frac{m_A v_{Ai} + m_B v_{Bi} - m_B v_{Bf}}{m_A} = \frac{1000\,kg \cdot 20\,\frac{m}{s} + 1200\,kg \cdot \left(10\,\frac{m}{s} - 15\,\frac{m}{s}\right)}{1000\,kg} = 14\,\frac{m}{s}.$$

Answer:

$$v_{Af} = 14\,\frac{m}{s}.$$

https://www.AssignmentExpert.com