What is velocity, because it describes both speed and direction?

Velocity is a vector quantity. It has both, magnitude and direction. Velocity is the rate of change in the position of a body with respect to a frame of reference. One component is the magnitude of velocity which is speed. The other one is its direction.

Explanation:

Speed is a scalar quantity.

Velocity is a vector quantity.

There are two types of quantities:

1. Scalar quantity:

A scalar quantity is a quantity which is described by its magnitude alone.

2. Vector Quantity:

A vector quantity is a quantity which is described completely by both, its magnitude and direction.

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.

answer and explanation;