Answer:
Speed of car for first 30 minutes = 30 km h^{-1}
Speed of car for next 1 hour = 40 km h^{-1}
(a) total distance travelled by the car
First case
Speed = distance / time
distance = speed x time
= 30 x 0.5 ---- (30 min = 0.5 hour)
= 15 km ---- (i)
Second case
speed = 40 km h^{-1}
distance = 40 km x 1
= 40 km ---- (ii)
Adding (i) and (ii)
Total distance = 15 km + 40 km
= 55 km
(b) total time of travel = 0.5 hr + 1.0 hr = 1.5 hr
(c) average speed = total distance travelled/total time taken
= 5.5 km/ 1.5 hr
= 36.67 km h^{-1}
Explanation:
hope it helps
