Answer:
cell pohnes convert sound waves into radio waves
electromagnetic waves used in cellphone communications are called: radio waves
To send out a radio signal far and wide.. it is called: broadcast
Explanation:
Answer:
Gravity
Explanation:
Gravity pulls things down to earth and it is a force
Chemistry deals with the study of elements-- their properties, chemical reactions and their compounds. This science includes the study of how these elements or compounds are formed. The history of chemistry is divided to 4 periods.
Black Magic, Alchemy, Traditional Chemistry and Modern Chemistry comprised these periods.
How did the early chemists determine which of the substances are elements? Long time ago, chemists knew which substances could not be broken down and that mixtures are broken down through chemical means. Through the said process, they were able to identify which are elements from the substances they have tested.
Answer:
speed of the mass is 3.546106 m / s
Explanation:
given data
mass = 77.3 g = 77.3 × 
kg
spring constant k = 12.5 N/m
amplitude A = 38.9 cm = 38.9 ×
m
to find out
the speed of the mass
solution
we will apply here conservation energy that is
K.E + P.E = Total energy ..................1
so that Total energy = K.E max = P.E max
we know amplitude so we find out first P.E max that is
PE max = K.E + P.E
(1/2)kA² = (1/2)mv² + (1/2)kx²
kA^² = mv²+ kx²
so here v² will be
v² = k(A² - x²) / m
v = √[(k/m)×(A² - x²)] ............2
here x = (1/2)A so from from 2 equation
v = √[(k/m)×(A² - (A/2)²)]
v = √[(k/m)×(3/4×A²)]
now put all value
v = √[(12.5/ 77.3 × )×(3/4×(38.9 ×)²)]
v = 3.546106 m / s
speed of the mass is 3.546106 m / s
