Question

if a body attains a velocity of 20m/s in 30 seconds starting from rest, find its acceleration.​

Answer 1

Answer:

Explanation:

Initial velocity(u)=0

Final velocity(v)=20

Answer 2

Given :-

$u=0 ms^{-1}\\v=20 ms^{-1}\\t=30s$

Required to find :-

$a=?\\s=?$

Equations required :-

$v=u+at\\2as=v^2-u^2$

Procedure :-

Let us use the first equation of motion and plug in the values.

$v=u+at\\20=0+30a\\30a=20\\\\a=\frac{20}{30}ms^{-2}\\\\a= \frac{2}{3}ms^{-2}$

Now let us plug in the values in third equation of motion.

$2as=v^2-u^2\\2(\frac{2}{3}) s=20^{2} -0^2\\\\\frac{4}{3}s=400\\\frac{s}{3}=100\\s=300m$