Question

A racing car has a uniform acceleration of 4 metre per second square.What distance will it cover in 10 s after start?​

Answer 1

Given :-

• Acceleration (a) = 4 m/s².

• Time (t) = 10 sec.

• Initial velocity (u) = 0 m/s.

To find :-

• Required distance (s) = ?

Solution :-

$\underbrace{\bf\red{{Using\:{1}^{st}\:equation\:of\:motion}}}$

we know that,

$\pink{\bigstar}{\underline{\boxed{\bf\green{v=u+at}}}}$

$\rm\longrightarrow\:v=0+4\times\:10$

$\rm\longrightarrow\:v=0+40\:m/s$

$\rm\longrightarrow\:v=40\:m/s$

Now,

$\underbrace{\bf\pink{{Using\:{3}^{rd}\:equation\:of\:motion}}}$

$\blue{\bigstar}{\underline{\boxed{\bf\orange{{v}^{2}={u}^{2}+2as}}}}$

$\rm\longrightarrow\:{(40)}^{2}={(0)}^{2}+2\times\:4\times\:s$

$\rm\longrightarrow\:1600=0+8\:s$

$\rm\longrightarrow\:-8\:s=0-1600$

$\rm\longrightarrow\:-8\:s=-1600$

$\rm\longrightarrow\:s=\cancel\dfrac{-1600}{-8}$

$\rm\longrightarrow\:s=200\:m$

Hence,the required distance will be 200 m.

$\underbrace{\bf\:More\:Information}$

2rd equation of motion :-

$\gray{\bigstar}{\underline{\boxed{\bf\purple{s=ut+\dfrac{1}{2}a{t}^{2}}}}}$

Answer 2

200 metres

Explanation:

Given:

Initial velocity = u = 0 m/s

Acceleration = a = 4 m/s²

Time taken = 10 seconds

To find:

Distance it will cover in 10 seconds after start

First using first equation of motion:

V=u+at

V=0+4×10

V=0+40

V=40 m/s

Now using third equation of motion:

V²-u²=2as

40²-0²=2×4×s

1600-0=8s

1600=8s

s = 1600/8

s = 200 metres

The distance covered by the racing car after start is equal to 200 metres