A bicyclist is biking down a board walk by the water, the mass of him and his bike is 78.0 kg. He is moving at a constant 8.90 m/s when a bird flies into him from the front at 1.20 m/s and is unable to fly away. If they are now travelling at 8.20 m/s, what is the mass of the bird? 7.80 kg 5.81 kg 73.9 kg 6.66 kg

This problem can be solved using the principle of conservation of momentum. The total momentum before the collision is equal to the total momentum after the collision.

Step 1: Calculate the initial momentum of the system (bicyclist and bird) before the collision. The bird's initial momentum is 0 because it's flying towards the bicyclist (opposite direction), so we only need to calculate the bicyclist's momentum.

Momentum = mass x velocity Momentum (bicyclist) = 78.0 kg x 8.90 m/s = 694.2 kg*m/s

Step 2: Calculate the final momentum of the system (bicyclist, bird, and bike) after the collision.

Momentum (bicyclist, bird, and bike) = (78.0 kg + mass of bird) x 8.20 m/s

Step 3: Set the initial momentum equal to the final momentum and solve for the mass of the bird.

694.2 kg*m/s = (78.0 kg + mass of bird) x 8.20 m/s Divide both sides by 8.20 m/s to isolate the mass of the bird on one side of the equation:

mass of bird = (694.2 kg*m/s ÷ 8.20 m/s) - 78.0 kg

Solving this equation will give you the mass of the bird.