Question

An auto travels at a rate of 25 km/hr for 4 minutes, then at 50 km/hr for 8 minutes, and finally at 20 km/hr for 2 minutes. Find the total distance covered in km and the average speed for the complete trip in m/s.

Please answer it correctly​

Answer 1

Answer:

v1= 25 km/hr

t1= 8 min =(8/60)h

d1= distance traveled in 4 min =v1 t1=25 (4/60) =1.67 km

v2= 50 km/hr

t2= 8 min =(8/60) h

d2 = distance traveled in 8 min =v2 t2= 50 (8/60) =6.67

v3 = 20 km/hr

t3 = 2 min = (2/60) h

d3 = distance traveled in 2 min = v3 t3 = 20 (2/60) =0.67 km

d = total distance

Total distance is given as

d = d1 + d2 + d3

d = 1.67 + 6.67 + 0.67

d = 9.01

t = total time = t1 + t2 + t3 = 4+8+2= 14 min = (14/60) hour

average speed is given as

v = d/t

v = 9.01/(14/60)

v = 38.6 km/hr

v = 38.6 (5/18) m/s

v = 10.7 m/s