A CAR COVERS A DISTANCE OF 40 METRE IN 10 secondS. FIND IT'S SPEED IN a) M/ SEC b) KM/HR
Answers
Answer:
Distance covered by car 180 km in 5 hours
(i) Distance covered in 1 hour = \frac{180}{5}=36km
5
180
=36km
Distance covered in 3 hours = 3 x 36 = 108 km
(ii) To cover a distance of 180 km , time taken = 5 hours
To cover a distance of 1 km , time taken = \frac{5}{180}
180
5
To cover a distance of 54 km, time taken = \frac{5}{180}\times54=1.5hours
180
5
×54=1.5hours
Answer:
Letx consider, x= total distance covered by the car,
Time taken to complete the half distance with velocity v=40km/h,
t
1
=
2×40
x
=
80
x
hr. . . . .(1)
The time taken to complete another half distance with velocity u=60km/h
t
2
=
2×60
x
=
120
x
hr
The total time taken, t=t
1
+t
2
t=
80
x
+
120
x
=
48
x
hr
The average speed of the car,
v
avg
=
x/48
x
=48km/h
The correct option is B.