On a frictionless horizontal air table, puck a (with mass 0.254 kg ) is moving toward puck b (with mass 0.367 kg ), which is initially at rest. after the collision, puck a has velocity 0.123 m/s to the left, and puck b has velocity 0.651 m/s to the right.

what was the speed vai of puck a before the collision?

calculate δk, the change in the total kinetic energy of the system that occurs during the collision.

Explanation:

According to the law of conservation of linear momentum, the total momentum of both pucks won't be changed regardless of their interaction if no external forces are acting on the system.

Being and the masses of pucks a and b respectively, the initial momentum of the system is

Since b is initially at rest

After the collision and being and the respective velocities, the total momentum is

Both momentums are equal, thus

Solving for

The initial kinetic energy can be found as (provided puck b is at rest)

The final kinetic energy is

The change of kinetic energy is

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.

overcharge is the right answer system