Question

a car travelling wiyh velocity of 80 km/h slowed down to 44 km/h in 15s .the retardation is

Answer 1

v-u=at
u=80 km/h=22.22m/s
v=44km/h=12.22m/s
t=15s
v-u=at
12.2-22.22=a*15
-10/15=a
a=-2/3m/$s^{2}$

Answer 2

Answer:

The retardation is -0.66 m/s².      

Step-by-step explanation:

Given : A car travelling with velocity of 80 km/h slowed down to 44 km/h in 15s.

To find : The retardation is ?

Solution :

The initial velocity is u=80 km/hr.

The final velocity is v=44 km/hr.

Converting into m/s,

$u=80\times\frac{5}{18}=22.22m/s$

$v=44\times\frac{5}{18}=12.22$

The time taken is t=15 s.

Applying kinetics formula,

$v=u+at$

Substitute values,

$12.22=22.22+a(15)$

$15a=-10$

$a=-\frac{10}{15}$

$a=-0.66$

Therefore, The retardation is -0.66 m/s².