Question

(12) The basic unit of speed is
A. km / min B. m / min
C. km/h D. m/s
(13) A car moves with a speed of 40 km/h for 15 minutes and thenwith a speed of 60 km/h for next 15 minutes. The total distancecovered by the car is
km.
A. 100 B. 25 C. 15 D.10​

Answer 1

Answers : d and b

1. The basic unit if speed is m/s

2. Solution :-

› Speed of the car, v1 = 40 km/h

› Time taken, t1 = 15 minutes = ¼ h

› Distance covered, s1 = v1*t1

› s1 = 40*¼ = 10 km

› Speed of the car, v2 = 60 km/h

› Time take, t2 = 15 minutes = ¼ h

› Distance covered, s2 = v2*t2

› s2 = 60*¼ = 15 km

Therefore, total distance covered, s = s1 + s2

› s = 10 km + 15 km

› s = 25 km

Hope it helps!

Answer 2

Answer:

12. m/s

13. total distance= (40×1/4)+(60×1/4)

=10+15

=25km