Question

a person driving a carvin a straight line with uniform velocity 36km/h he suddenly applied brake and the car stopped after travelling a distance 10 m waht is the time and acceleration​

Answer 1

Answer:a=-5m/s² and t=2s

Explanation:u=36km/h or 10m/s

v=0m/s

s=10m

From equation :2as=v²-u²

a=v²-u²÷2s

=(0)²-(10)²÷(2×10)

=-100÷20

-5m/s²

Now with the first equation of motion we know that:v=u+at

By rearranging: t=(v-u)÷a

=(0-10)÷-5

=2s

HOPE IT HELPS!!

Answer 2

Correct Question :

• a person driving a car in a straight line with uniform velocity 36 km/h he suddenly applied brake and the car stopped after travelling a distance 10 m what is the time and acceleration​

Given:

• initial velocity=36 km/hr
• final velocity = 0 m/s
• distance traveled by the car=10 m

To find :

• time taken
• acceleration

Unit conversion :

we need to convert km / hr into m/s in order to do this we need to multiply by 5 /18

initial velocity

let us denote initial velocity of the car as' u '

$u=36\dfrac{km}{hr} =36\dfrac{5}{18} =10\dfrac{m}{s}$

Solution:

First we need to find the  acceleration of the car

by using the third kinematic equation we get ,

$\bigstar\large{\boxed{ \mathtt {v^{2} =u^{2} +2as}}$

here,

• v=final velocity
• u=initial velocity
• a=acceleration
• s=distance

Now substituting the given values in the above equation we get ,

$\rightarrow \mathtt {u^{2} = - 2as}$

$\rightarrow \mathtt {a= -\dfrac{u^{2} }{2s} }$

$\rightarrow \mathtt {a= - \dfrac{100}{2\times 10} }$

$\rightarrow \boxed{\mathtt {a= - 5\dfrac{m}{s^{2} } }}$

Note: here the negative sign denotes deceleration

_________________________________________________________

Now in order to find the  time taken

Using the first kinematic equation ,

$\bigstar\large{\boxed{ \mathtt {v=u+at}}$

here,

• v=final velocity
• u=initial velocity
• a=acceleration
• t =time taken

Now substituting the given values in the above equation we get ,

$\rightarrow \mathtt {u= -at}$

$\rightarrow \mathtt {t= \dfrac{u}{-a} }$

$\rightarrow \mathtt {t= \dfrac{10}{-(-5)} }$

$\rightarrow \boxed{\mathtt {t=2 sec }}$

Answer:

• acceleration of the car = -5 m/s^2
• time taken by the car = 2 seconds