An object travels 10 m in first 3 sec and 15 m in next 4 sec . then what is the velocity of object in end of 8 sec ?
Hello,
We know that, as per the Equation of Motion,
s = ut + 0.5 a t^2
So, for first 3 sec.,
10 = 3u + 0.5 x a x 9
So, 3u + 4.5a = 10.............. ( 1 )
Now, for next 4 sec.,
25 = 7u + 0.5 x a x 49
So, 7u + 24.5a = 25............ ( 2 )
Solving ( 1 ) and ( 2 ), we get,
a = 0.12 m/s^2 and u = 3.15 m/s
Now, also as per the Equation of motion,
v = u + at
So, For 8 sec.,
v = ( 3.15 ) + ( 0.12 x 8 )
So, v = 4.11 m/s
Hence, The velocity of object at the end of 8 seconds will be 4.11 m/s
Best Wishes.