Arocket is launched at an angle of 39◦ above the horizontal with an initial speed of 90 m/s. it moves for 7 s along its initial line of motion with an acceleration of 19 m/s 2 . at this time its engines fail and the rocket proceeds to move as a projectile. the acceleration of gravity is 9.8 m/s 2 . find the maximum altitude reached by the rocket. answer in units of m.

Y=1370.23m

Explanation:

The motion have two moments the first one the time the initial velocity is accelerating then when the engines proceeds to move as a projectile

Now the motion the rocket moves as a projectile so:

Now the final velocity is the initial in the second one

The maximum altitude Vf=0

So total altitude is both altitude of the motion so:

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.