Question

The car decreases it's speed from 80kmph to 60kmph in 5 sec what is the average acceleration of the car explain detail...​

Answer 1

Intial Speed of Car(u)=80 km/h

In m/s=80×5/18=200/9 m/s

Final Speed of Car after 5 seconds(v)=60 km/h

In m/s=60×5\18=150/9 m/s

Time(t)=5 s

Using Equation of Motion

v=u+at

$\frac{150}{9} = \frac{200}{9} + a \times 5 \\ \\ \frac{150}{9} - \frac{200}{9} = 5a \\ \\ \frac{ - 50}{9} = 5a \\ \\ a = - \frac{50}{9 \times 5} \\ \\ a = - \frac{10}{9}$

Acceleration=-10/9 m/s²

or in Decimal

10/9=1.11

Acceleration=-1.11 m/s²

Answer 2

Step-by-step explanation:

$\sf\red{Initial~speed~of~car~(u)}$ = 80 km/hr

$\sf\red{In~m/s}$ = 80 × $\frac{5}{18}$

• $\frac{200}{9}$ m/s

$\sf\red{Final~speed~of~car~(v)}$ = 60 km/hr

$\sf\red{In~m/s}$ = 60 × $\frac{5}{18}$

• $\frac{150}{9}$ m/s

$\sf\red{Time~(t)}$ = 5 seconds

$\sf\underline\green{From~equation~}$ :-

• v = u + at

→ $\frac{150}{9} {=} \frac{200}{9}$ {+} {a} \times{5}[/tex]

→ $\frac{150}{9} {-} \frac{200}{9} {=} {5a}$

→ $\frac{-50}{9} {=} {5a}$

→ $\sf{a} {=} \frac{50}{9 \times 5}$

→ $\sf{a} {=} \frac{-10}{9}$ m/s²

:. The acceleration of the car is $\sf\green{\frac{-10}{9}}$ m/s² or $\sf\pink{-1.1}$ m/s².