Question 13 (4 points)
use the diagram to answer the questions.
which part of the seismometer does not shake during an earthquake?
the frame
the spring
the rotating drum
the mass and pen

The mass and pen

Explanation:

Seismograph is the device used for measuring the movement of earth such as earthquake, volcanic eruptions or other movements. A seismograph can record the motion as small a 1/10,000,000 cm. Seismograph consist a recording device. Now we have electronic seismograph but earlier we had pen and drum seismograph in which pen and mass remains stable and does not shake during movement.

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.