False.
Theories are hypotheses that have been shown to accurately and predictably explain results obtained through repeated experimentation, to the point where the hypothesis can be assumed to be true. Then, such a hypothesis would be considered a theory.
Haven't taken physics but I would assume if her friend is standing in front of her that you would add up the speeds and get 30 km/hr.
Answer:
D. 18.60
Explanation:
By the law of conservation, the momentum is neither loss nor gained but instead transfered. When they crash into each other, and stick, they combine to create a total mass of 215 kg. Since the momentum is transfered, the two objects, combined, have a total momentum of 4000 kg-m/s. We know that momentum equals mass times velocity. You then divide 4000 by 215 and get approximately 18.6 m/s