Question

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

Answer 1

Answer:

110 m/s

Explanation:

s = ut + $\frac{1}{2}$a$t^{2}$

20 = 2u + 1/2* a *4

20 = 2u + 2a

u + a = 10-------1

160 = 6u + 1/2*a*36

80=3u + 9a---------2

from 1 and 2

u= -20/3 m/s

a = 50/3 m/s^2

v = u + at

  =  -20/3 + 50*7/3

   = 110 m/s