Answer:
If research results can be replicated, it means they are more likely to be correct.
Since he wonders, then according to the formal, methodical procedures of scientific inquiry, he should not go running off and trying stuff before he <em>forms a hypothesis that can be tested.</em>
In his mind, at some point, he should say to himself <em>"Self ! It seems to me that if salt is added to water, it makes the water boil at a higher temperature than pure water does."</em>
And only THEN, with this statement in mind, he's ready to design an experiment to test it.
Answer: vl = 2.75 m/s vt = 1.5 m/s
Explanation:
If we assume that no external forces act during the collision, total momentum must be conserved.
If both cars are identical and also the drivers have the same mass, we can write the following:
m (vi1 + vi2) = m (vf1 + vf2) (1)
The sum of the initial speeds must be equal to the sum of the final ones.
If we are told that kinetic energy must be conserved also, simplifying, we can write:
vi1² + vi2² = vf1² + vf2² (2)
The only condition that satisfies (1) and (2) simultaneously is the one in which both masses exchange speeds, so we can write:
vf1 = vi2 and vf2 = vi1
If we call v1 to the speed of the leading car, and v2 to the trailing one, we can finally put the following:
vf1 = 2.75 m/s vf2 = 1.5 m/s
