Question

an object start moving from intial velocity is 20/m2 and he cover 1.5km with acceleration of 4m/s2 fibd the time​

Answer 1

Explanation:

given

u= 20m/s

s= 1.5km= 1500m

a= 4m/s

s= ut+1/2at²

1500= 20t+1/2×4t²

2t²+20t-1500=0

t²+10t-750=0

t= (-10±√100+3000)/2

= -5±5√31 seconds

but -5+5√31 >0

ans= 5(√31 -1) seconds