How much time is required for an airplane to reach its takeoff speed of 77m/a if it starts from rest and its average acceleration is 8.2m/s^2?

The time required is t = 9.39 [s]

Explanation:

To solve this problem we must use the following equation of kinematics.

where:

Vf = final velocity = 77 [m/s]

Vo = initial velocity = 0

a = acceleration = 8.2 [m/s²]

t = time [s]

The initial speed is zero, since the airplane begins its movement from rest. The initial speed is zero, since the aircraft begins its movement from rest. Another important fact is that the sign of acceleration is positive since the plane is accelerating, that is, its speed is increasing.

Now replacing:

77 = 0 + (8.2*t)

t = 9.39 [s]

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.

b.a device that inputs heat into a cool object