. An object starting from rest travels 20 m in first 2 s and 160 m in next 4 s


An object starting from rest travels 20 m in first 2 s and 160 m in next 4 s. What will be the velocity after 7 s from the start

Best Answer

20. S1 = ut + 1/2at 2 or 20 = 0 + 1/2 a (2)2 or a = 10 m s-2

 υ = u + at = 0 + (10 × 2) = 20 m s-1

s2 = 160 = υt + 1/2 a (t)2 = (20 × 4) + (1/2 a × 16) a = 10 m s-2

Since acceleration is the same, we have υ = 0 + (10 × 7 ) = 70 m s-1

= 50 m = initial difference in height Thus, difference in height does not vary with time

Talk to Our counsellor