CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A car travels from A to B at a speed of 20 km/h and returns at a speed of 30 km/h. The average speed of the car for the whole journey is

A
25 km/h
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
24 km/h
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
50 km/h
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
5 km/h
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 24 km/h
While going from A to B, let the speed be V1 and from B to A the speed be V2.
V1=20 km/h
V2=30 km/h
If d be the distance AB. Then we can say:
Time required for A to B=t1=dV1
Time required for B to A=t2=dV2

Average speed, v=total distancetotal time
v=d+dt1+t2
v=2ddV1+dV2
v=2V1V2V1+V2

v=2×20×3020+30
v=24 km/h

flag
Suggest Corrections
thumbs-up
1
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon