Question

A body travelled distance of 2m in 2 second 2.2m in next 4second ?what will the velocity of a object at the end of 7 second of object?​

Answer 1

Explanation:

Distance covered in first 2 seconds =2m

=> ut +½at²=2m

=>2u+2a=2m (t=2seconds)

=>u+a=1———(I)

Distance covered in last 4 seconds=2.2m

Total distance in 6 seconds =2.2+2=4.2m

=>ut+½at²=4.2m

=>6u+18a=4.2m (t=6 seconds)

=>u+3a=0.7-(ii)(dividing both sides by 6)

Now subtracting equation (ii) form (I),we get—

-2a=0.3

=>a= -0.15m/s²

Putting this value in equation (I), we have--

u=1.15m/s

Now , velocity at the end of 7th second = u+at = 1.15 + (-0.15*7)=1.15–1.05m/s = 0.1m/s

Hence, velocity at the end of 7th second is 0.1m/s or 10cm/s.