Question

3. A football player runs at 8 m/s and plows into a 80 kg referee standing on the field causing

the referee to fly forward at 5.0 m/s. If this were a perfectly elastic collision, what would the
mass of football player be?

Answer 1

Step-by-step explanation:

To solve for the mass of the football player, we can use the conservation of momentum principle, which states that the total momentum before a collision is equal to the total momentum after the collision. Assuming the collision is perfectly elastic, we have:

m1 * v1 + m2 * v2 = m1 * v1' + m2 * v2'

where m1 is the mass of the football player, v1 is the initial velocity of the football player, m2 is the mass of the referee, v2 is the initial velocity of the referee, v1' is the final velocity of the football player, and v2' is the final velocity of the referee.

Since the referee is at rest before the collision, we can set v2 = 0. Plugging in the given values, we get:

m1 * 8 + m2 * 0 = m1 * (-8) + m2 * 5

Expanding and solving for m1:

8m1 = -8m1 + 80

16m1 = 80

m1 = 5 kg

So, the mass of the football player is 5 kg.