Apendulum of length l is suspended from the ceiling of an elevator. when the elevator is at rest the period of the pendulum is t. how does the period of the pendulum change when the elevator moves upward with constant acceleration?
a) the period decreases.
b) the period increases if the upward acceleration is more than g/2 but decreases if the upward acceleration is less than g/2. c) the period does not change.
d) the period becomes zero.
e) the period increases.

A)The period decreases.

Explanation:

Given that

Length of the pendulum = L

Time period = T ( at rest condition)

At rest condition only gravitational acceleration g act downward.

At rest

When acceleration will move upward with acceleration a ,then

Therefore we can say that time period of the pendulum will decrease ,because g+a is more than g.

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.