Question

A particle starts from rest with an acceleration 2m * s ^ - 2 . If the force producing acceleration is applied for 10 s then determine the velocity of the particle after 20 s.
(a) 40m * s ^ - 1
(c) 20m * s ^ - 1
(b) 10m * s ^ - 1
(d) 30m * s ^ - 1​

Answer 1

$\large\underline\bold\red{Given:-}$

• Initial velocity , u = 0m/s

• Acceleration , a = 2m/s²

• Time taken , t = 20 s

$\large\underline\bold\red{To\:Find:-}$

• Final velocity , ( v )

$\large\underline\bold\red{Solution:-}$

⠀⠀⠀⠀⠀⠀⠀⠀According to the Question

It is given that the particles start from rest & accelerate at 2m/s² . We have to calculate the final velocity of particles after 20s .

Using 1st equation of motion :-

ㅤㅤㅤㅤㅤㅤㅤv = u + at

where,

• v denote final velocity

• u denote initial velocity

• a denote acceleration

• t denote time taken

Substitute the value we get

$:\implies$ v = 0 + 2×20

$:\implies$ v = 0 + 40

$:\implies$ v = 40 m/s

Hence, the final velocity of the particles is 40m/s

So, the required option is (a) 40m/s .

$\rule{300px}{.4ex}$

Answer 2

$:\implies$ v = 0 + 2×20

$:\implies$ v = 0 + 40

$:\implies$ v = 40 m/s

(a) 40m/s .