Answer:They come in different kinds, called elements, but each atom shares certain characteristics in common. All atoms have a dense central core called the atomic nucleus. Forming the nucleus are two kinds of particles: protons, which have a positive electrical charge, and neutrons, which have no charge
Explanation:
Answer:
Explanation:
Let the intensity of the noise be represented by I
Given that
40dB = 10 log 10 ( I /I•) ........ 1
I• is the lowest or threshold intensity of sound made.
I represents the intensity of the sound/ noise
The intensity of noise of 1000flies will be
β = 10 log 10 (1000I/I•)
Open up the bracket
β = 10 log 10(1000)+ 10 log 10(I/I•)
10 log 10(10^3)+10 log 10(I/I•)
3×10(10 log 10) +10 log 10(I/I•)
Recall, 10 log 10 = 1
30×1 + 10 log 10(I/I•).........2
Put equation 1 into 2
β =30+40
= 70db
Answer:
Fossils tell us when organisms lived, as well as provide evidence for the progression and evolution of life on earth over millions of years.
Explanation:
As the world changes, plants and animals change with it. Aside from a few living fossils, the species we see today are very different from species that lived in the past. Thus, the fossil record can be used to show that organisms changed to meet new conditions. ... This is the result of evolution of species over time.
Answer:
Choice A: approximately
, assuming that the two pistons are connected via some confined liquid to form a simple machine.
Explanation:
Assume that the two pistons are connected via some liquid that is confined. Pressure from the first piston:
.
By Pascal's Principle, because the first piston exerted a pressure of
on the liquid, the liquid will now exert the same amount of pressure on the walls of the container.
Assume that the second piston is part of that wall. The pressure on the second piston will also be
. In other words:
.
To achieve a force of
, the surface area of the second piston should be:
.
The power dissipated across a component can be calculated through the formula P=I^2xR
Substituting the values in we get P=(0.5)^2x10=2.5W