Q. A train has a speed of 60 $km/h$. for the first one hour and 40 $km/h$ for the next half hour. Its average speed in $km/h$ is
A) 50
B) 53.33
C) 48
D) 70
Explanation
(b) Distance travelled by train in first 1 $hour\ $is 60 $km\ $and distance in next 1/2 hour is 20 $km.$
So Average speed = $\frac{Total\ distance\ }{Total\ time} = \frac{60 + 20}{3/2}$
= 53.33 $km/hour$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.