Question

distance travelled by particle is given by x = 0.4t2 find speed at t = 10 sec ​

Answer 1

8 meter/sec

GIVEN:-

distance travelled by a particle

x = 0.4t²

TO FIND:-

speed at t = 10 sec

SOLUTION:-

x = 0.4t²

=> velocity (dx/dt)

= (d/dt) 0.4t²

= 0.4×2t

=> v = 0.8t

initial velocity (u) = 0.4×2×0 = 0

at t = 10 sec

v = 0.8×10

= 8 unit/sec

( since unit of distance is not given)

let it may meter

=> v = 8m/sec

THEREFORE, VELOCITY AT( t= 10 sec)

= 8m/sec

HOPE THIS HELPS YOU

Another method:-

given, x = 0.4 t²

comparing with x = ut+(1/2) at²

u= 0, a = 0.8 m/sec²

=> velocity (v) = u+at

at time t = 10 sec

v = 0+0.8×10

= 8m/sec