1). To describe the length of a classroom, a student can use any unit
he feels like using. Some units will produce ridiculous numbers, though.
The most convenient numbers will result from using meters or centimeters.
If the room is, say, 20 feet long, then that's about 0.0061 kilometer, or
about 610 centimeters, or about 6.1 meters.
Meters is probably best.
2).
A). Kelvin: time. No. Kelvin is a unit of temperature.
B). second: time Yes. Second is a unit of time.
C). meter: volume No. Meter is a unit of length or distance.
D). gram: temperature. No. Gram is a unit of mass.
3). A plate near Hawaii grows about 11 cm per year.
So it grows 11 cm in the first year, and another 11 cm in the second year.
The total growth in 2 years is (11cm + 11cm) = 22 cm .
4). A slower plate in the Arctic moves slightly less than 2.5 cm per year.
It moves ...
slightly less than 2.5 cm in the 1st year
slightly less than 2.5 cm in the 2nd year
slightly less than 2.5 cm in the 3rd year
slightly less than 2.5 cm in the 4th year
slightly less than 2.5 cm in the 5th year
slightly less than 2.5 cm in the 6th year
slightly less than 2.5 cm in the 7th year
slightly less than 2.5 cm in the 8th year
slightly less than 2.5 cm in the 9th year
and
slightly less than 2.5 cm in the 10th year
for a grand total of
(slightly less than 2.5 cm x 10) = less than 25 cm in 10 years.
Answer:
7.5 * 10^(14) Hz to 9.375 * 10^(14) Hz.
Explanation:
The minimum wavelength, λ₁ = 320 nm = 3.2 * 10⁻⁷ m
The corresponding frequency can be obtained by using the formula of speed of light:
c = λ₁ * f₁
f₁ = c / λ₁
f₁ = ( 3 * 10^8) / (3.2 * 10^(-7))
f₁ = 9.375 * 10^(14) Hz
The maximum wavelength, λ₂ = 400 nm = 4 * 10⁻⁷ m
The corresponding frequency can be obtained by using the formula of speed of light:
c = λ₂ * f₂
f₂ = c / λ₂
f₂ = ( 3 * 10^8) / (4 * 10^(-7))
f₂ = 7.5 * 10^(14) Hz
The frequency range of UVA is therefore 7.5 * 10^(14) Hz to 9.375 * 10^(14) Hz.
For conservation of energy we have to:
mgH=mv²/2
Clearing
<span> v=sqrt(2gH)
Then, by definition
</span><span> F=Δp/Δt= Δ(mv)/ Δt=m Δ(v)/Δt=
</span> =m[sqrt(2gH)-0]/Δt= m[sqrt(2gH)]/ Δt
the answer is
F=m[sqrt(2gH)]/ Δt
Answer: 45.95 m/s
Explanation:
When we talk about circular motion, the object's <u>acceleration</u> (which is a vector quantity) has two components: the <u>centripetal acceleration</u> always directed to the center of the circular track and the <u>tangential acceleration</u> which is tangent to the circular path.
Since both vectors are perpendicular to each other, the magnitude of can be calculated by the Pithagorean Theorem:
(1)
Where:
where is the speed and is the radius of the circle
can be calculated knowing the initial speed () and final speed () of the car and the time () it takes to accelerate at this constant rate:
Rewritting (1):
(2)
Isolating :
(3)
(4)
Finally:
Some commonly used techniques might be distillation and magnetism.
Distillation is basically a method of separating liquid mixture by basically boiling and condensing the different liquids. Since liquids don't have the same boiling points. one will evaporate first, and the other liquid or liquds will remaim.
Magnetism is a method of separating solid mixtures. One or some solids will get atracted to the magnet and the others will remain. Note that this only works if one of the solids has a magnetical property.
Hope it helped,
Happy homework/ study/ exam!