Question

4. A racing car has a uniform
acceleration of 4 m s?, What
distance will it cover in 10 s after
start?​

Answer 1

Answer:

initial velocity zero

s=v+.5at^2

answer=200m

Answer 2

$\large \mathfrak { \underline{ \red {Correct \: Question \: }}}:-$

$\small \rm A \: racing \: car \: has \: a \: uniform \: acceleration \: of \\ \small \rm 4 \: ms {}^{ - 2} .What \: distance \: will \: it \: cover \: in \: 10 \: s \: \\ \small \rm after \: start \: ?$

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

• Initial velocity , u ⇏ 0 m/sec

• Acceleration , a ⇏ 4 m/ sec²

• Time taken , t ⇏ 10 sec

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

• Distance covered by the car , s ⇏ ?

$\large \mathfrak { \underline{ \red {Formula \: }}}:-$

$\small \star \bigstar \rm \: s⇢ ut + \frac{1}{2}at {}^{2} \bigstar \star$

$\large \mathfrak { \underline{ \red {Substituting \: }}}:-$

We know,

$\small\rm \:↬ s⇢ ut + \frac{1}{2}at {}^{2}$

$\small\rm \:↬ s⇢ 0 \times 10 + \frac{1}{2} \times 4 \times {10}^{ 2}$

$\small\rm \:↬ s⇢ 0 + \frac{1}{ \cancel2 } \times \cancel4 \times {100}$

$\small\rm \:↬ s⇢ 2 \times 100$

$\small\rm \:↬ s⇢ 200 \: m$

Hence, the distance that the racing car will cover in 10 s after start is 200 m.

$\large \mathfrak { \underline{ \red {Full \: Explaination \: }}}:-$

• In this query, Acceleration, Initial velocity and Time taken is given .

• As the car starts from the rest so the Initial velocity will be 0 m/sec.

• Here, it is given that we have to find out the Distance , (s) .

• Using Newton's law of motion we can find the required answer.

• As here distance (s) is given , we know two formulae to find it. That is :- 2nd Equation of motion and Third equation of motion.

• As in the Third equation of motion , we need Final velocity ( v ) which is not mentioned in this query.

• So , the right formula to use here is the 2nd equation of motion.

• Applying the 2nd equation of motion , we will get the required Value.

$\pink\bigstar{ \underline { \underline { \bf{↬ \purple{ ExpLore \: MoRe \: ForMuLa}↫}}}} \green \bigstar$

$\small \green\bigstar {\underline {\boxed { \bf {s = v \times t }}}} \red\bigstar$

where ,

• s ➟ distance

• v ➟ speed

• t ➟ time taken

───※ ·❆· ※───

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

where,

• u ➟ Initial velocity

• v ➟ Final velocity

• a ➟ Acceleration

• t ➟ time taken

───※ ·❆· ※───

$\small \green\bigstar {\underline {\boxed { \bf {s=ut + \frac{1}{2}at {}^{2} }}}} \red\bigstar$

where,

• s ➟ distance

• u ➟ Initial velocity

• t ➟ time taken

• a ➟ Acceleration

───※ ·❆· ※───

$\small \green\bigstar {\underline {\boxed { \bf {2as=v {}^{2} - {u}^{2} }}}} \red\bigstar$

where,

• a ➟ acceleration

• s ➟ distance

• v ➟ final velocity

• u ➟ initial velocity

───※ ·❆· ※───