Answer:
a) I₁ / I₂ = 9, b) I₁ / I₂ = 25
Explanation:
a) The amount of light that can pass through a telescope is the intensity of the light
I = P / A
where A is the area of the mirror and P is the incident power that is the same in all telescopes
P = I₁ A₁ = I₂ A₂
where subscript 1 is for the 2 m diameter telescope and subscript 2 for the 6 m diameter telescope
The mirror area is
A = π r²
r = d / 2
we substitute
I₁ π d₁² /4 = I₂ π d₂² / 4
I₁ / I₂ = (d₂ / d₁) ²
we calculate
I₁ / I₂ = (6/2) ²
I₁ / I₂ = 9
b) d₂ = 15 inch and d₁ = 3 inc
let's calculate
I₁ / I₂ = (15/3) ²
I₁ / I₂ = 25
Solve the following problem. A force of 5N is being applied to the right, and a force of
3N is being applied to the left. What is the net force?
A- 15 N
B- 8 N
C- 7N
D- 2N
Answer:
D 2N
Explanation:
these are opposite forces so one becomes negative and the other positive that is
-3+5=2 or 5-3=2
A skydiver weighing 200 lbs with clothes that have a drag coefficient of .325 is falling in an area that has an atmospheric density of 1.225 kg/m2 (and assuming that altitude has a negligible effect on atmospheric density). The skydiver can change the body orientation from straight-erect with a cross-sectional area of 6 sqft to a belly-flat cross-sectional area of 24 sqft. Calculate the terminal velocity of the person when the body has straight and when the body has belly-flat orientations. Calculate the terminal velocity on these two different orientations.
Answer:
The right solution is:
(a) 89.455 m/s
(b) 44.73 m/s
Explanation:
The given values are:
Mass,
m = 200 lbs
or,
= [tex]\frac{200}{2.205} \ kg[/tex]
= [tex]90.7 \ kg[/tex]
Air's density,
[tex]\delta = 1.225 \ kg/m^3[/tex]
Drag coefficient,
[tex]C_d=0.325[/tex]
When body is straight, area,
[tex]A_1=6 \ ft^2[/tex]
As we know,
Terminal velocity,
⇒ [tex]V_t=\sqrt{\frac{2W}{C_d \delta A} }[/tex]
or,
⇒ [tex]=\sqrt{\frac{2mg}{C_d \delta A} }[/tex]
At straight orientation,
⇒ [tex]V_t'=\sqrt{\frac{2\times 90.7\times 9.8}{0.325\times 1.225\times 0.558} }[/tex]
⇒ [tex]=\sqrt{\frac{1777.72}{0.223}}[/tex]
⇒ [tex]=89.455 \ m/s[/tex]
When belly flat,
⇒ [tex]V_t''=\sqrt{\frac{2\times 90.7\times 9.8}{0.325\times 1.225\times 0.558\times 4} }[/tex]
⇒ [tex]=\sqrt{\frac{1777.72}{0.889} }[/tex]
⇒ [tex]=44.73 \ m/s[/tex]
PLEASE HELP I WILL MARK BRAINLYIST!!!!!!!!!
All of the matter in the universe formed after the big bang. Scientists
predicted that hydrogen and helium would be the most abundant elements.
What did scientists discover?
A. The universe has 73% hydrogen and 25% helium, which does not
support the big bang theory
B. Planets are made mostly of other elements, which does not
support the big bang theory
C. Stars are made mostly of other elements, which supports the big
bang theory
D. The universe has 74% hydrogen and 24% helium, which supports
the big bang theory.
Answer:
The answer is D. Here is proof . Plz mark brainliest
Explanation:
A boat that can travel at 4.60 km/h in still water crosses a river with a current of 1.80 km/h. At what angle must the boat be pointed upstream to travel straight across the river
Answer:
The angle the boat must be pointed upstream is 69⁰
Explanation:
Check the image uploaded for the diagram;
Given;
speed of the boat on still water, = 4.6 km/h
speed of the boat on a river with current, = 1.8 km/h
The angle the boat must be pointed upstream is calculated as follows
[tex]tan(\theta) = \frac{4.6}{1.8} \\\\tan(\theta) = 2.556\\\\\theta = tan^{-1}(2.556)\\\\\theta = 68.63^0\\\\\theta = 69^0[/tex]
In a double-slit experiment, the third-order maximum for light of wavelength 510 nm is located 17 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 670 nm is then projected through the same slits. Part A How far from the central bright spot will the second-order maximum of this light be located
Answer:
14.9 mm
Explanation:
We know dsinθ = mλ where d = separating of slit, m = order of maximum = 3 and λ = wavelength = 510nm = 510 × 10⁻⁹ m
Also tanθ = L/D where L = distance of m order fringe from central bright spot = 17 mm = 0.017 m and D = distance of screen from slit = 1.6 m
So, sinθ = mλ/d
Since θ is small, sinθ ≅ tanθ
So,
mλ/d = L/D
d = mλD/L
Substituting the values of the variables into the equation, we have
d = 3 × 510 × 10⁻⁹ m × 1.6 m/0.017 m
d = 2448 × 10⁻⁹ m²/0.017 m
d = 144000 × 10⁻⁹ m
d = 1.44 × 10⁻⁴ m
d = 0.144 × 10⁻³ m
d = 0.144 mm
Now, for the second-order maximum, m' of the 670 nm wavelength of light,
m'λ'/d = L'/D where m' = order of maximum = 2, λ' = wavelength of light = 670 nm = 670 × 10⁻⁹ m, d = slit separation = 0.144 mm = 0.144 × 10⁻³ m, L' = distance of second order maximum from central bright spot and D = distance of screen from slit = 1.6m
So, L' = m'λ'D/d
So, substituting the values of the variables into the equation, we have
L' = 2 × 670 × 10⁻⁹ m × 1.6 m/0.144 × 10⁻³ m
L' = 2144 × 10⁻⁹ m²/0.144 × 10⁻³ m
L' = 14888.89 × 10⁻⁶ m
L' = 0.01488 m
L' ≅ 0.0149 m
L' = 14.9 mm
The temperature of a body is from 200 to 300C.The change of temp at absolute scale is
Answer:
mark me brainliest
Explanation:
The change of temperature at absolute scale is. A. 3.73 K
Answer:
373K
Explanation:
300°c - 200°c =100°c
Absolute scale means Kelvin scale so
0°c= 273°c
100°c = 100 + 273
=373K
True False: Marke each statement as true or false.
shift
1. Light intensity affects the rate of photosynthesis.
in
2. Energy is required by all organisms for life.
3. The ability of a plant to repair tissue depends on respiration.
4. The gas needed for photosynthesis is carbon dioxide (CO2).
5. Plants only carry on photosynthesis, not respiration.
6. Respiration can occur without photosynthesis.
Answer:
1) true 2) true 3) true 4) true 5) false 6) false
Explanation:
Describe each of the FITT training principles. (Site 1
Answer:
The FITT principles are an exercise prescription to help participants understand how long and how hard they should exercise. FITT is acronym that stands for Frequency, Intensity, Time, and Type. FITT can be applied to exercise in general or specific components of exercise.
Explanation:
Question 15 of 25
You feel warm sitting next to a bright light. Which type of heat transfer are
Experiencing?
Answer:
radiation
Explanation:
Which of the following means that an
image is real?
A. +do
B. +di
c. -di
D.-do
Answer:
B
Explanation:
After 60 days, 100g of a certain element has decayed to only 12.5g.
What is the half- life of this element?
А
30 days
B.
8 days
С
20 days
D
5 days
Answer:
8 days
Explanation:
A current of 5 a flows in a copper wire for 20 s. how many coulombs of charge passed through the wire in this time?
Answer:
I think so too
Explanation:
:*
The power output of a car engine running at 2500 rpm is 500 kW . You may want to review (Pages 574 - 577) . Part A How much work is done per cycle if the engine's thermal efficiency is 20.0 %
Answer:
Explanation:
2500 rpm = 2500 / 60 rps ( revolution per second )
= 41.67 rps .
power output = 500 kW
thermal efficiency = 20 %
power input = (100 /20) x 500 kW
= 2500 kW .
work done per second = 2500 kJ
work done per cycle = 2500 / 41.67
= 60 kJ .
We have that the workdone per cycle is mathematically given as
Wc=12.00KJ
Workdone per cycle of engineQuestion Parameters:
The power output of a car engine running at 2500 rpm is 500 kW
Generally the work done per cycle is mathematically given as
Wc=500*1/41.666
Where
=2500rev/60sec
=41.666
Meaning one cycle takes 1/41.666
Hence
Wc=500*1/41.666
Wc=12.00KJ
For more information on work
https://brainly.com/question/756198
The diagram below shows a person swinging a hammer.
Which position has the least amount of kinetic energy?
A-1
B-2
C-3
D-4
An electrical insulator is a material that:
A) contains no charge
B) does not allow electrons to flow
C) has more protons than electrons
D) must be a crystal
Answer:
Option B is appropriate for this question
How long does it take for a 3.5 kW electric water heater to heat 40 kg of water? from 20 ° C to 75 ° C? The specific heat capacity of water is 4190 J/kgK PLEASE HURRY ITS A TEST
Answer:
2633.7 s
Explanation:
From the question,
Heat lost by the water heater = Heat gained by the water
Applying,
P = cm(t₂-t₁)/t.................. Equation 1
Where P = power of the heat, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature, t = time
make t the subject of the equation
t = cm(t₂-t₁)/P.............. Equation 2
From the question,
Given: c = 4190 J/kgK, P = 3.5 kW = 3500 W, m = 40 kg, t₁ = 20°C, t₂ = 75°C
Substitute these values into equation 2
t = 4190×40(75-20)/3500
t = 9218000/3500
t = 2633.7 s
please help, im having trouble can you please explain how to do it
Answer:
independent and the second one with the (-8, 1, -3)
How does rainwater contribute to aquatic succession
Answer:
Rain water carries sediment and then these accumulate on the bottom of ponds, lakes and wetlands. This accumulation build up over time and eventually, the water disappears (because they sink into the ground) and the area once covered with water becomes land.
using the image provided, which moon phase is next?
Answer:
Waning Crescent
Answer: waxing crescent
Explanation:
is it possible to have rainbows during the fine sunny day? Explain your answer.
Answer:
As long as there is rain, a rainbow is possible. Rain is possible on a sunny day, and is known as a sunshower.The rainbow can be observed in a sunny day if the water droplets are present in air and the sun rays pass through it reaches the eye of the observer. In this situation, the observer can see a rainbow.
or
If you happened to look up at the sky this past weekend, you might have noticed a rare and beautiful sight: iridescent rainbow clouds, but not a drop of rain in sight. This phenomenon is known, fittingly, as cloud iridescence or irisation. The effect is not unlike seeing a rainbow painted on the clouds.
The illustration shows ?
A)open circuit
B)broken circuit
C)series circuit
D)parallel circuit
Answer:
D)parallel circuit
Explanation:
the components are placed parallel from eachother
A child moving at constant velocity carries a 2 N ice-cream cone 1 m across a level surface. What is the net work done on the ice-cream cone?
Answer:
2 Joule
Explanation:
Work=force *dISPLACMENT
2N*1M
2 JOUL
b. Why are the resources listed in part (a) considered "renewable"?
Answer:
I would need to see the part a to be more specific but this may help:
resources like solar, water, wind are considered renewable because they will never run out, they can be replenished over and over again. There will always be a sun (and if there wasn't then we'd have bigger conserns than renewable energy) and the wind will always blow. It can never run out because you use too much unlike coal and fossil fuels.
Hope this helps!
True or False? To observe physical properties in matter, the matter must change into a new substance.
Select the correct answer. A body travels 10 meters during the first 5 seconds of its travel, and it travels a total of 30 meters over the first 10 seconds of its travel. What is its average speed during the time from t = 5 seconds to t = 10 seconds? A. 2 meters/second B. 3 meters/second C. 4 meters/second D. 5 meters/second E. 6 meters/second
Answer:
2 m/s
Explanation:
...........................
Answer:
A:2 m/s
Explanation:
Plato
A magnetic field of 0.27 T exists in the region enclosed by a solenoid that has 599 turns and a diameter of 9.29 cm. Within what period of time must the field be reduced to zero if the average magnitude of the induced emf within the coil during this time interval is to be 12.8 kV
Answer: [tex]8.54\times 10^{-5}\ s[/tex]
Explanation:
Given
The initial magnetic field is [tex]B=0.27\ T[/tex]
No of turns [tex]N=599\ \text{turns}[/tex]
Diameter of the solenoid [tex]d=9.29\ cm[/tex]
Induced EMF [tex]E=12.8\ kV[/tex]
Induced emf is the product of no of turns and rate of change of flux.
[tex]\Rightarrow E=-N\cdot \dfrac{\Delta \phi }{\Delta t}\\\\\Rightarrow E=-N\cdot \dfrac{\Delta (B\cdot A)}{\Delta t}\\\\\Rightarrow E=-NA\cdot \dfrac{\Delta B}{\Delta t}\\\\\text{Insert the values}\\\\\Rightarrow 12.8=-599\times \pi r^2\cdot \dfrac{(0-B)}{\Delta t}\\\\\Rightarrow \Delta t=\dfrac{599\times \pi \times (4.64\times 10^{-2})\times 0.27}{12.8\times 10^3} \\\\\Rightarrow \Delta t=854.71\times 10^{-7}\ s\\\\\text{Taking absolute value}\\\Rightarrow \Delta t=8.54\times 10^{-5}\ s[/tex]
HELP PLZ
Calculate the resistivity of a metal of length 2m at 20°C having the resistance
of 20 ohm and diameter 0.3mm?
Answer:
40*C
Explanation:
Please help... I'm confused on what I represents in terms of solving the total current. Would variable would I be singling out?
Answer:
the researcher say hi for us the best pa the best of us are going out to eat that I can get my money toward a little bit but the best of luck to be at work by then and we will see what the status
Help
An object’s mass 300 kg is observed to accelerate at the rate of 4 m/s^2. Calculate the force required to produce this acceleration. *
1. 1000 N
2 .75 N
3. 1200 N
4. 1250 N
a spring has a spring constant of 330 n/m. how far is the spring compressed when 150 newtons of force are used?
a. 0.0014 meters
b. 0.45 meters
c. 2.2 meters
d. 5.0 meters
show your work
Answer:
I think its B
Explanation: