The velocity of a car changes from 10 m/s east to 30 m/s east in 4 seconds what is the acceleration of the car

a = 5 m/s²

Explanation:

Acceleration is the rate of change of velocity. Acceleration can only occur if their is change in the velocity of an object. Acceleration is said to be the change of velocity with time. Acceleration can be represented mathematically as

a = Δvelocity/Δt = change in velocity/ change in time

From the equation acceleration means the difference between initial velocity and final velocity divided by the time required to change velocity.

let

a = acceleration

u = initial velocity

v = final velocity

t = time

therefore,

a = v - u/t

From the question

u = 10 m/s

v = 30 m/s

t = 4 secs

a = 30 - 10 / 4

a = 20/4

a = 5 m/s²

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.