Question

Two football players are running towards each other. Player Ahas a mass of 80 kg and is running at a speed of 5 m/s, playerB has a mass of 100 kg and is running at 4 m/s. If the twoplayers grab onto each other when they make contact, whatis their speed after the collision?

Answer 1

Answer:

The speed of the players after collision = 0 m/s

Explanation:

For player A

$\begin{gathered} Mass,\text{ m}_A=80kg \\ Speed,\text{ u}_A=5\text{ m/s} \\ \end{gathered}$

For player B

He is moving in opposite direction to player A

$\begin{gathered} Mass,\text{ m}_B=100kg \\ \\ Speed,\text{ u}_B=4\text{ m/s} \end{gathered}$

Let their speed after collision be v

Using the conservation principle:

$\begin{gathered} m_Au_A+m_Bu_B=(m_A+m_B)v \\ \\ 80(5)+100(-4)=(80+100)v \\ \\ 400-400=180v \\ \\ 0=180v \\ \\ v=\frac{0}{180} \\ \\ v=0\text{ m/s} \end{gathered}$

The speed of the players after collision = 0 m/s

This means that the two players come to a halt after collision.