Final answer:
The man's speed after hitting the rock is calculated using the conservation of momentum. The momentum before and after the collision must be the same. The man will fly forward at a speed of 5.5 m/s.
Step-by-step explanation:
The question describes a conservation of momentum scenario that is common in physics problems. When the man and scooter hit the rock, the scooter stops, but the man continues to move forward. To determine the speed at which the man flies forward after hitting the rock, we will use the law of conservation of momentum. The momentum before and after the incident must be equal because there are no external forces acting in the horizontal direction (ignoring air friction for simplicity).
Before the collision, the total momentum (pinitial) is given by the mass of the man plus the scooter times their shared velocity, which can be calculated as (100kg + 10kg) × 5m/s = 550kg×m/s. After the collision, the scooter's momentum is 0 because it is at rest, and the only momentum considered is that of the man. Therefore, the momentum of the man (pfinal) is equal to his mass times his velocity after the collision (100kg × vman).
Setting pinitial equal to pfinal gives us: 550kg×m/s = 100kg × vman. Solving for vman, we find that vman = 550kg×m/s ÷ 100kg = 5.5m/s. Therefore, the correct answer to the question is B) 5.5 m/s.