Question

An object moves at an average speed of 10m/s for 20 seconds it then moves at 20m/s for 30 seconds. Then The average speed of object over 50 seconds is ​

Answer 1

Answer:

Suppose the acceleration is a then using the second equation of motion, s=ut+21at2

and putting t=2sec and u=10m/s 

we get 20=10×2+a×2

or a=0 that is uniform motion.

Answer 2

Answer:

The average speed of the object over 50 seconds is 40m/s

Explanation:

In the first two cases,

the speed and time, both were increasing uniformly I.e. by 10 units

Hence,

the average speed over 50 seconds will be 40 m/s