the only equation you really need is d=vt, or t=d/v. That gives you
114t = 79t+36
35t=36
t = 36/35
That's how long it takes B to overtake A.
In that time, A travels 79*36/35 = 81.26 km
You can think of this another way by noting that B is traveling 35 km/hr faster than A. So, it just takes 36/35 hours to make up the 35 km.
(b) Knowing that B travels 35 km/hr faster than A, it's easy to figure how much ahead it is after 30s = 1/120 hr
Two cars are traveling along a straight road. Car A maintains a constant speed of 79 km/h and car B maintains a constant speed of 114 km/h. At t = 0, car B is 36 km behind car A.
(a) How much farther will car A travel before car B overtakes it?
? km
(b) How much ahead of A will B be 30 s after it overtakes A?
Please use kinematics equations! Thank you!!
2 answers
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