A 1500 kg car traveling at 35 m/s hits its brakes and comes to rest in 5 seconds. Calculate the force applied by the brakes. (hint: solve for a first) Show all steps!!

We are given:

m = 1500 kg

initial velocity (u) = 35 m/s

final velocity (v) = 0 m/s

time (t) = 5 seconds

acceleration = a m/s/s

Force (f) = F  newtons

Solving for acceleration:

Using the first equation of motion:

v = u + at

replacing the variables

0 = 35 + a(5)

a = -35/5

a = -7 m/s/s

Force applied by the brakes:

From newton's second law of motion:

F = ma

replacing the variables

F = (1500)(-7)

F = -10500 N

Therefore, the force applied by the brakes is -10500 N, we have a negative sign since the force is being applied opposite to the direction of motion

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.

i think its c if i'm wrong