At a certain instant an auto driver is driving at the speed of 30km/hr.Then he uniformly accelerates his auto and after 2.5 minutes the speed of his auto becomes 60km/hr.what is the average speed of the auto?what is the value of uniform acceleration during the given interval of time.
please explain and answer.
Answers
Answer:uniform acceleration =0.2 m/sec2
Average speed= 7.5km/hr
Explanation:
Acceleration =v-u/time
Acceleration =
60-30/2.5min
Convert 2.5min into sec
1min=60sec
2.5min=?sec
Cross multiplication
2.5*60sec =150sec
Acceleration =
60-30/150=30/150=1/5
=0.2m/sec2
Average speed= total distance/2
1st find distance
S=d/t
30km/hr=d/150sec
Convert 150sec or 2.5min
Into hour
60 min = 1hr
2.5min=?hr
hr=2.5/60
D1=30*2.5/60=12.5km
D2=60*2.5/60=2.5km
Average speed= d1+d2/2
=12.5+2.5/2
=15/2
=7.5km/hr
Hello, initial velocity = 30 * 5/18 m/s
Final velocity = 60 * 5/18 m/s
So change in velocity = 60-30 (5/18 m/s)
Time taken = 2.5 min = 2.5 * 60 s = 25 * 6 s = 150 s
Hence acceleration (uniform) = change in velocity /time taken
==> 30 * 5/18 * 1/150 = 1/18 m/s²
As acceleration is uniform average velocity = u + v / 2 = 60+30/2 = 90/2 = 45 km/h