Respuesta :
Answer:
(a) 48 km
(b) 102 km
(c) 48.96 km/h.
Explanation:
Assuming that at first, the car travels from point A to point B, then the cat returns from point B to point C.
As the car traveled from point A to point B in 1 hour 15 minutes with a speed of 60 km/h.
Using distance = speed x time, so
Distance traveled from A to B is
[tex]d_{AB}= 60 x 1.25=75[/tex] km [ as time = 1 h 15 min = 1.25 h]
Stop time at point B is 5 minutes.
For the return journey, from point B to C:
Speed = 10 m/s
Time = 45 minutes = 45 x 60 seconds = 2700 seconds
Distance traveled from point B to C is
[tex]d_{BC}=[/tex] 10 x 2700 = 27000 meters
as 1000 meters = 1 km, so
[tex]d_{BC}=[/tex] 27 km.
(a) The final position of the car from the starting point A is the distance between points A and C.
[tex]d_{AC}=[/tex]75 -27=48 km.
Hence, the car is 48 km away from point A.
(b) Total distance traveled,
[tex]d= d_{AB}+d_{BC}=[/tex]75+27=102 km.
(c) Total time taken
t= 1.25 hour + 5 minutes + 45 minutes
= 5/4 hour + 5/60 hour + 45/60 hour [ as 1 hour = 60 min]
=25/ 12 hours.
Total distance traveled, d= 102 km [ from part (b)]
Average speed = (Total distance traveled)/(Total time taken)
=102/ (25/12)= 48.96 km/h.
Hence, the average speed of the car is 48.96 km/h.
