Final answer:
The question involves the high school physics concepts of conservation of momentum and kinetic energy, and it seeks to determine the new velocity of a car after colliding with a deer, based on their initial velocities and masses.
Step-by-step explanation:
The question pertains to conservation of momentum and kinetic energy, which are key concepts in high school Physics. To find the velocity of the 900-kg car just after it hits the 150-kg deer moving in the same direction, we use the conservation of momentum, which states that the total momentum of a closed system remains constant if no external forces act on it. The initial momentum of the car and deer system is given by the sum of their individual momenta, which is (900 kg × 30.0 m/s) + (150 kg × 12.0 m/s). Since the deer remains on the car after the collision, the final mass of the system is 900 kg + 150 kg. Setting the initial momentum equal to the final momentum (M₁V₁ + m₁v₁ = (M+m)V), we can solve for the final velocity (V).