Question

a car decrease its speed from 100 km/h to 80km/h in 10 seconds. find acceleration of car

Answer 1

Answer:

s1=100kmph s2 = 80kmph

time = 10kmph

a= 100 -80 /10

= 20/10 = 2 kmph

Answer 2

Answer:

A car decreases its speed from 100 km/h to 80km/h in 10 seconds. The acceleration of the car will be  $0.55556\ m/s^2$

Explanation:

Acceleration (a) of an object can be defined as the rate of change of velocity with respect to time.

It is given by the expression,

$a = \frac{v-u}{t}$                 ...(1)

where u is the initial velocity of the object, v is the final velocity and t is the time taken.

In the question, it is given that,

$u = 100\ km/h = 100\times \frac{5}{18} = 27.7778\ m/s$

$v = 80\ km/h = 80\times \frac{5}{18} = 22.2222\ m/s$

$t = 10\ s$

Substitute these values into the equation(1)

$a = \frac{22.2222- 27.7778}{10} = -0.55556\ m/s^2$

The negative sign indicates the retardation of the car.