1.Write true or false. If the statement is false, tell why. A. Rocks can break down into sediments.
B. Rocks can change from sedimentary to metamorphic.
C. Coal is an example of an igneous rock.
D. New rocks form over time.
E. Marble is a sedimentary rock.
F. Kimberlite is an igneous rock.
G. All rocks are made of minerals.
H. Rocks and minerals are the same.
I. All minerals are made of rocks.
J. A mineral with a hardness of 6 will scratch a mineral with a hardness of more than 6.
2. What is the hardest known mineral?

answer: electrons

explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length

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.

report!

explanation:

physics means: "the branch of science concerned with the nature and properties of matter and energy. the subject matter of physics, distinguished from that of chemistry and biology, includes mechanics, heat, light and other radiation, sound, electricity, magnetism, and the structure of atoms."