Arock is thrown upward with a velocity of 15 meters per second from the top of a 34 meter high cliff, and it misses the cliff on the way back down. when will the rock be 3 meters from the water, below? round your answer to two decimal places.

At 4.47 seconds rock will be 3m meters from the water.

Explanation:

We need to find when will the rock be 3 meters from the water.

That is rock has traveled (34-3) meters below.

Displacement = 31 m

Since the displacement is along down we need to give negative sign.

Displacement = -31 m

Initial velocity = 15 m/s

We have equation of motion

Substituting

Neglecting negative time.

time, t = 4.47 seconds.

So at 4.47 seconds rock will be 3m meters from the water.

the body's situation won't change the forces are equal opposit and on the same body

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.