when the gas in a balloon is heated, the balloon expands. what are the correct signs of heat and work for this change?
a. +q, -w
b. -q, +w
c. +q, +w
d. -q, -w
things that could :
w=work q= heat
q= heat work
+ heat absorbed + work done by
- heat released - work done on

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.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle