Aball is kicked from a location 7, 0, −8 (on the ground) with initial velocity −11, 19, −5 m/s. the ball's speed is low enough that air resistance is negligible. (a) what is the velocity of the ball 0.4 seconds after being kicked? (use the momentum principle! ) v = incorrect: your answer is incorrect. m/s

Explanation:

given,

location of the ball ⟨7,0,−8⟩

initial velocity of the ball ⟨-11,19,−5⟩

time = 0.4 s

speed of the ball = ?

using Momentum Principle

change in momentum = Force x time

Net force acting in this case will be equal to force due to gravity because air resistance is negligible.

F_net = F_g = ⟨0 ,-9.8 m , 0⟩

now,

hence, the velocity of the ball 0.4 s after being kicked is equal to

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.

in physics zero. in muscle fatigue could be high