Answer:
bias refers to effects that a conclusion that may be incorrect, as for example when a researcher patient knows what treatment is being given, to avoid bias a blinded study may be done
The answer is:
d.It’s a composite because it’s a mixture of cement, sand, and other granular pieces.
The explanation:
Concrete is a composite, since it is composed of various elements like sand, gravel & water.
Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along with finer materials such as sand. Cement, most commonly Portland cement, is associated with the general term "concrete.
Answer:
1500 mph
Explanation:
Take east to be +x and north to be +y.
The x component of the velocity is:
vₓ = 889 cos 0° + 830 cos 59°
vₓ = 1316.5 mph
The y component of the velocity is:
vᵧ = 889 sin 0° + 830 sin 59°
vᵧ = 711.4 mph
The speed is found with Pythagorean theorem:
v² = vₓ² + vᵧ²
v² = (1316.5 mph)² + (711.4 mph)²
v = 1496 mph
Rounded to two significant figures, the jet's speed relative to the ground is 1500 mph.
Answer:
0.6275 metres
Explanation:
v = fl
125.5 = 200 * wavelength
125.5 / 200 = wavelength = 0.6275m
To solve this problem we will apply the ideal gas equations for which the product of pressure and volume is defined, as the equivalent between the ideal gas constant by the amount of matter and the temperature, mathematically this equation is described as
Here,
P = Pressure
V = Volume
R = Ideal gas Constant
T = Temperature
n = Number of molecules
The pressure is in atmospheres, and considering the units of the other values we have finally that,
Replacing,
Multiplying the number of moles by Avogadro's number we have,
Therefore the number of ozone molecules in the Earth's ozone layer are