Question

Two football players with mass 85 kg and 110 kg run directly toward each other with speeds 4 m/s and 7 m/s respectively. If they grab each other as they collide, what is the combined speed of the players just after the collision?

A) 1 m/s
B) 2 m/s
C) 3 m/s
D) 4 m/s

Answer 1

The combined speed of the football players just after the collision is approximately 5.69 m/s.

Step-by-step explanation:

When two objects collide, momentum is conserved. Momentum is equal to the mass of an object multiplied by its velocity. In this case, the initial momentum of the first football player is (85 kg) * (4 m/s) = 340 kg·m/s, and the initial momentum of the second player is (110 kg) * (7 m/s) = 770 kg·m/s.

Since they grab each other and stick together, their total mass after the collision is 85 kg + 110 kg = 195 kg. Therefore, the combined speed of the players just after the collision can be calculated by dividing the total momentum of the system (340 kg·m/s + 770 kg·m/s = 1110 kg·m/s) by the total mass (195 kg). This gives us a combined speed of 1110 kg·m/s ÷ 195 kg = 5.69 m/s.

So, the correct answer is not given in the options. The combined speed of the players just after the collision is approximately 5.69 m/s.