physics
posted by thomas on .
A person travels by car from one city to another with diﬀerent constant speeds between
pair of cities. She drives for 31.5 min at
89.6 km/h, 11.8 min at 101.8 km/h, and
58.5 min at 36.4 km/h, and spends 24.8 min
eating lunch and buying gas.
Find the distance between the initial and
ﬁnal cities along this route.
Answer in units of km

Dt=89.6km/60min*31.5min+
101.8km/60min*11.8min+36.4km/60min*58.5=
Tot. Dist.
T = t1 + t2 + t3 + t4. = Tot. min.
T/60min/h = T in hours.
r(avg) = Dt/T