High School

A 110-kg tackler moving at 2.4 m/s meets head-on and tackles a 93-kg halfback moving at 6.4 m/s. What will be their mutual speed immediately after the collision?

Express your answer to two significant figures and include the appropriate units.

Answer :

Final answer:

Using the law of conservation of momentum, the mutual speed of the tackler and the halfback after the collision can be found to be approximately 4.23 m/s.

Explanation:

Using the law of conservation of momentum, we can find the mutual speed of the tackler and the halfback after the collision. The law of conservation of momentum states that the total momentum of a system before a collision is equal to the total momentum after the collision, assuming no external forces are acting on the system. In this case, the initial momentum of the tackler is given by:

Initial momentum of tackler = mass of tackler * velocity of tackler

= 110 kg * 2.4 m/s = 264 kg·m/s

The initial momentum of the halfback is:

Initial momentum of halfback = mass of halfback * velocity of halfback

= 93 kg * 6.4 m/s = 595.2 kg·m/s

Since momentum is conserved, the total initial momentum is equal to the total final momentum:

Total initial momentum = Total final momentum

264 kg·m/s + 595.2 kg·m/s = (mass of tackler + mass of halfback) * final velocity

859.2 kg·m/s = (110 kg + 93 kg) * final velocity

859.2 kg·m/s = 203 kg * final velocity

final velocity = 859.2 kg·m/s / 203 kg

final velocity ≈ 4.23 m/s

Therefore, the mutual speed of the tackler and the halfback immediately after the collision is approximately 4.23 m/s.