Question

Calculate the average speed of a complete round trip in which the outgoing 220 kmkm is covered at 92 km/hkm/h , followed by a 1.0-hh lunch break, and the return 220 kmkm is covered at 55 km/hkm/h . Express your answer to two significant figures and include the appropriate units.

Answer 1

60 km/hr

Step-by-step explanation:

220 km is covered at 92km/hr in the round trip

There is 1 hour lunch break

During the return of the round trip 220 km is covered at 55km/hr

The first step is to calculate the total distance

= 220km + 220km

= 440km

The time spent during the entire round trip can be calculated as follows

= (220/92) + 1 + (220/55)

= 2.3913 + 1 + 4

= 7.3913

Therefore the average speed can be calculated as follows

= distance/ time

= 440/7.3913

= 59.52

= 60km/hr (approximated to 2 significant figures)

Hence the average speed is 60 km/hr