Question

A body starts from rest and moves with a uniform acceleration of until it travels a distance of 800m, find the final velocity?

Answer 1

Here , s= 800

          a = 4 m/s2

          u  = 0

          v  =  2

Using v2 = u2+ 2 as

            v2 = 0+2*800*4

                  = 1600

             v = 40 m/s

I hope you like it. If you like it then please mark me as brainiliest.

Answer 2

Correct Question:

A body starts from rest and moves with a uniform acceleration of 4m/s² until it travels a distance of 800m, find the final velocity?

Given:

• Initial velocity is 0m/s [As the body starts from rest]
• It moves with an Acceleration of 4m/s²
• It travels Distance of 800m

To Find:

• Final Velocity of the body

★ Formula Used:

$\nrightarrow\sf{S=ut+\large{\frac{1}{2}}a{t}^{2}}$

$\nrightarrow\sf{V=u+at}$

Where,

• S is Displacement
• u is Initial velocity
• t is time of motion
• a is acceleration
• v is Final Velocity

Concept:

Here, concept of Motion and Rest is used. We are given with that the body starts from rest that means it's initial velocity is 0 and starts with an Acceleration until it travels a distance. We have to find the final velocity. We know that From First equation of motion, i.e v=u+at we can find the Final velocity. But, For finding so we firstly need to find the time taken. Using Second equation of motion i.e, s=ut+1/2×at2 We can find the time taken.

_____________________________________

Solution:

Let's Firstly find out the times taken by using Second equation of motion.

$\rightarrow\sf{S=ut+\large{\frac{1}{2}}a{t}^{2}}$

» Distance, s = 800 m

» Initial velocity, u = 0m/s

» Acceleration, a = 4m/s²

Substituting all values in the Formula:

$\rightarrow\sf{800=0\times t+\large{\frac{1}{2}}\times 4\times {t}^{2}}$

$\rightarrow\sf{800= \large{\frac{1}{2}}\times 4\times {t}^{2}}$

$\rightarrow\sf{800=2{t}^{2}}$

$\rightarrow\sf{\large{\frac{800}{2}}={t}^{2}}$

$\rightarrow\sf{{t}^{2}=400}$

$\rightarrow\sf{t=\sqrt{400}}$

$\rightarrow\bold{t=20}$

Hence, Time taken by the body is 20 seconds.

Now, let's find out the Final velocity. By using First equation of motion.

$\implies\sf{v=u+at}$

» Initial velocity, u = 0m/s

» Acceleration, a = 4m/s²

» Time taken, t = 20 sec

Substituting all values in Formula:

$\implies\sf{v=0+4\times 20}$

$\implies\bold{v=80}$

Hence, Final velocity of the body is 80 m/s.

Required Answer:

$\: \: \: \: \: \: \leadsto\underline{\color{purple}{\text{Final\: velocity\: of\: the\: body\: is\: 80\: m/s}}}$