Question

General kinematics problem.

"Anna is returning from vacation driving down the Sunshine Highway. She travels for a stretch (SA) at a speed of 110 km/h. Then, due to an increase in traffic, Anna is forced to reduce her speed by travelling the second part of the journey (SB) at 60 km/h. The total distance and duration of the trip are 350 km and 4.0 hours respectively.
-> Calculate the time intervals needed to travel SA and SB
-> Calculate the distances covered in the two sections SA and SB".

The results I should get by doing the exercise are in the attached picture.

If you could explain the various steps in the problem you would be doing me a huge favor. Thanks!​

Answer 1

Explanation:

What we know:

Sa + Sb = 350 km

Ta + Tb = 4h

S = Vt

With these equations above we can write a system of equations and find Tb, as you see in the picture(s).

After having Tb you can easily find Ta and then Sa and Sb. Hopefully it was clear.