Answer:
N = N0 e^-kt calling k the decay constant
70 = N0 e^-2 kt
35 = N0 e^-15 k
2 = e^(-2 + 15) k
.693 = 13 k
k = .0533
N0 = N e^kt
N0 = 70 e^(.0533 * 2) = 77.87
8.75 = 77.87 e^-(.0533 t)
ln .1124 = -.0533 t
t = -ln .1124 / .0533 = 41 yr
Is that statement true or false?
One adaptation of bioluminescent fish is that they may have lures that can produce light to help them hide from predators
A. true
B. false
Please Help!!!
Convert: 8 mm: ____________ cm
-1^10
centi=10 mm and mm=1/10=10^-1 cm
What did Dr Allan McInnes say was required in order to launch a satellite into space, at the necessary altitude and speed? What is required and why?
A 250 g sample of water with an initial temp of 98.8 c loses 7500 joules of heat. What is the final temperature of the water?
The final temperature of the water is 106.0 °C
From the question,
We are to determine the final temperature of water.
From the formula
Q =mcΔT
Where Q is the quantity of heat
m is the mass of substance
c is the specific heat capacity of substance
and ΔT is the change in temperature
Also,
ΔT = T₂ - T₁
Where T₂ is the final temperature
and T₁ is the initial temperature
Then, the formula can be written as
Q =mc(T₂ - T₁)
From the question
Q = 7500 J
m = 250 g
T₁ = 98.8 °C
Putting the parameters into the formula, we get
7500 = 250 × 4.184 (T₂ - 98.8)
(NOTE: specific heat capacity of water, c,= 4.184 J/g °C)
7500 = 1046 (T₂ - 98.8)
7500 = 1046T₂ - 103344.8
Then,
1046T₂ = 7500 + 103344.8
1046T₂ = 110844.8
∴ T₂ = 110844.8 ÷ 1046
T₂ = 105.9701 °C
T₂ ≅ 106.0 °C
Hence, the final temperature of the water is 106.0 °C.
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An book fell from a shelf 1.5 meters from the ground. If it took the book 3 seconds to hit the ground, what was the velocity of the book?
The initial velocity of the book before its hits the ground is 14.2 m/s.
The given parameters;
height of the book above the ground, h = 1.5 mtime of motion of the book, t = 3 secondsThe initial velocity of the book is calculated as follows;
h = ut + ¹/₂gt²
where;
u is the velocity of the book1.5 = 3u + (0.5 x 9.8 x 3²)
1.5 = 3u + 44.1
3u = 1.5 - 44.1
3u = -42.6
[tex]u = \frac{-42.6}{3} \\\\u = -14.2 \ m/s\\\\u = 14.2 \ m/s \ downwards[/tex]
Thus, the initial velocity of the book before its hits the ground is 14.2 m/s.
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what is the central idea for stacking rocks vertically to test the effects of forces
Answer:
You can see how forces can stack on one another by comparing the normal force of the bottom most rock to the normal force of the upper most rock.
Explanation:
Say you have 3 rocks all with mass m=3kg
These 3 rocks will all have the gravitational force of -29.4N (multiply 3kg by -9.8m/s^2)
If none of the rocks are stacked, then they all have the same normal force as well (29.4N)
However, stack them, and see how their normal forces change.
m1 will continue to have a normal force of 29.4N
m2 will now have a normal force of 58.8
m3 will now have a normal force of 88.2
Though they all retain the same gravitational force, their normal force changes depending on the forces acting down on them.
Mass 1 have no forces acting downwards other than gravity.
Mass 2 has the force of mass 1 and gravity acting down on it.
Mass 3 has the force of mass 1, mass 2, and gravity acting down on it.
the energy released by a nuclear fusion reaction is produced when
Answer:
atoms combine
Explanation:
Habiba and selehadin have measured the voltage across a resistor to be 5.26V and the current flowing through in to be 0.41A they work out the resistance .
habiba says the resistance is 12.8 ohms .selehadin disagrees and says that is 13 ohm .
who is correct?.
Considering the definitipn of current, voltage, power, and Ohm's law,
CurrentThe flow of electricity through an object, such as a wire, is known as current (I). Its unit of measurement is amps (A). So current is a measure of the speed at which the load passes through a given reference point in a specified direction.
VoltageThe conductive force (electrical pressure) behind the flow of a current is known as voltage and is measured in volts (V) (voltage can also be referred to as the potential difference or electromotive force). That is, voltage is a measure of the work required to move a charge from one point to another.
Resistance
Resistance (R) refers to the resistance or opposition that an element has to the passage of electric current. It is represented by the symbol Ω and indicates the resistance that an element offers to the passage of electricity.
This means that the greater the resistance to the passage of current, the lower the intensity or amount of electricity that passes through this conductor.
The resistance that is measured in ohms.
Ohm's law
Ohm's law indicates that the current through a circuit is directly proportional to its voltage or voltage and inversely proportional to the resistance it presents.
Mathematically, Watt's law is expressed:
[tex]I=\frac{V}{R}[/tex]
So if you want to find resistance, the expression for its calculation is:
[tex]R=\frac{V}{I}[/tex]
This caseIn this case, you know:
V= 5.26 VI= 0.41 AReplacing:
[tex]R=\frac{5.26 V}{0.41 A}[/tex]
Solving:
R= 12.8 ohms
Habiba is right. The resistance is 12.8 ohms.
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https://brainly.com/question/23205779?referrer=searchResultshttps://brainly.com/question/13485930?referrer=searchResultshttps://brainly.com/question/9813227?referrer=searchResultswrite two examples of machine which changes the direction of force
Answer:
Washign machine and swingset
Explanation:
a tennis ball is launched from the floor at a velocity of 90 m/a at an angle of 13 degrees to the horizontal. calculate its range
Answer:
~186
Explanation:
1) R= (V^2 × sin A ) /g
V=90 m/a
A= 13°
g= 9.8 or 10 (I will take 9.8 for right result)
R= (90^2 × sin 13) / 9.8 = 185.928932672 ~ 186
If the wind is blowing from north to south, where are the areas of high and low pressure?
Answer:
Wind is caused by differences in the atmospheric pressure. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds.
Our Earth is a rotating planet. Fast moving air is deflected by the Coriolis effect, except exactly on the equator. This defines the direction of cyclones, hurricanes, and typhoons rotation. The wind flow around a large cyclone is counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Wind forms when the sun heats one part of the atmosphere differently than another part. This causes expansion of warmer air, making less pressure where it is warm than where it is cooler. Air always moves from high pressure to lower pressure, and this movement of air is wind.
The high is west of you, and the low is east of you. (If you're in the northern Hemisphere.)
An automobile travels the first half of an 80.0 mi trip at 20.0 mi/h and the second half of the trip at 40.0 mi/h. What is the average speed for the entire trip?
This question involves the concepts of uniform speed motion and average speed.
The average speed for the entire trip is "26.67 mi/h".
First, we need to find out the total time taken for the entire trip. For that purpose, we will break the entire trip into two halves of uniform speed motion:
[tex]Total\ Time = t_1+t_2\\\\Total\ Time = \frac{s_1}{v_1}+\frac{s_2}{v_2}\\\\Total\ Time = \frac{40\ mi}{20\ mi/h}+\frac{40\ mi}{40\ mi/h}\\\\Total\ Time = 2\ h + 1\ h\\Total\ Time = 3\ h[/tex]
Now, the average speed for the entire trip will be:
[tex]Average\ Speed = \frac{Total\ Distance}{Total\ Time}\\\\Average\ Speed =\frac{80\ mi}{3\ h}[/tex]
Average Speed = 26.67 mi/h
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The attached picture explains the concept of average speed.
Multiples of the fundamental frequency created by plucking a string very quickly, several times in a row is called__________.
a.
pitch
c.
scales
b.
overtones
d.
percussion
Answer:
overtones
Explanation:
Lúc 7h sáng một xe xuất phát từ Bình Minh ra siêu thị Metro Hà Đông cách nhau 9,6km. Trên đoạn đường từ Bình Minh đến ngã ba Ba La cách nhau 7,2km xe đi với vận tốc 10m/s. Trên đoạn đường từ ngã ba Ba La đến Metro xe đi mất 3,2 phút.
a. Xác định thời gian xe đi đến siêu thị ? thời điểm xe đi đến siêu thị ?
b. Tính vận tốc trung bình của xe trên cả quãng đường từ Bình Minh đến siêu thị Metro Hà Đông ?
can u type in english?????
An object is known to have balanced forces on it. Which of the following would be a true statement?
If an object has a balanced force on it, there is a possibility that the object may be in a position i.e. there is no change in speed and direction of the body.
If the forces acting on an object is balanced, it means that the net force acting on the body is zero.
According to Newton's law of motion, an object will continue in a state of motion in a straight line unless acted upon by an external force.
This external force might be a balanced or unbalanced force. Hence if an object has a balanced force on it, there is a possibility that the object may be in a position i.e. there is no change in speed and direction of the body.
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When a 12 newton horizontal force is applied to a box on a horizontal
table top, the box remains at rest. The force of static friction acting on
the box is .....
The force of static friction acting on the box is greater than the applied horizontal force.
Force is known to be the reason for motion according to Newton's first law of motion. An object will move when it has been acted upon by an external force.
In this case, a box lying on a table has been acted upon by an external force of 12 newton but the box remains at rest. This simply means that the applied force is less than the force of static friction acting on the box.
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1.concave lens
A.distance between two waves
B.can be captured on screen
C.light of a wavelength
D.scattered incident light
E.convex lenses
F. distance to the focal point
G.light swinging in one direction
H.heat radiation
What to do here tell please.......
How would these two particle diagrams be classified?
A-) Both are pure substances each containing one type of compound
B-)Both are pure substances containing a mixture of elements
C-) Both are mixtures containing different types of compounds
D-) Both are mixtures containing more than one element
Answer:
A-) Both are pure substances each containing one type of compound
Which is true for every atom of an element?
A.
It can be seen with a magnifying glass.
B.
It is joined together with another atom.
C.
It has mass and volume.
D.
It is weightless.
Answer:
A
Explanation:
Every atom of an element has its own mass and volume as the atom is the smallest fundamental unit of the matter, therefore the correct answer is option C.
What is the matter?Anything which has mass to keep the same when comparing the hardness of the solid and occupies space is known as matter, mainly there are four states of matter solid liquid gases, and plasma.
As given in the problem statement we have to find the true statement from the given options that is true for every atom of an element,
The size of an atom of an element is a very small order of magnitude so it can not be seen with a magnifying glass, therefore, option A is not the correct response.
Thus, every atom of an element has its own mass and volume as the atom is the smallest fundamental unit of the matter, therefore the correct answer is option C.
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a proton, moving east, enters a magnetic field of a certain strength. because of this field the proton curves downward. what is the direction of the magnetic field?
Answer:
F = q V X B
Using the right hand rule (right hand screw) turn V into B to get direction of force which in this case is down
If V is east and F is down then one can see that B must be directed towards the south - turn V into B (south) and F will be directed downwards.
Which one is the right answer?
Newton’s second law of motion relates an objects acceleration to _____.
A. It’s mass
B. It’s velocity
C. The net force acting on it.
D. Two of the above
Answer:
C. The net force acting on it.
why is the saturated lapse rate less than the dry adiabatic lapse rate?
Answer:
(Hope this helps can I pls have brainlist (crown)☺️)
Explanation:
Lifting a saturated package causes it to expand and cool, resulting in vapour condensation. Condensation will release latent heat, partially counteracting the cooling. As a result, a saturated parcel's adiabatic lapse rate is smaller than an unsaturated parcel's.
Because moist air ascending condenses off its water vapour, the moist adiabatic lapse rate is lower than the dry adiabatic lapse rate (once saturation is attained). The air is considered to be saturated when the dew point temperature and air temperature are identical.
4. As Juan is going to take a shower, the soap falls out of the soap dish on to the
floor and Juan steps on it with a force of 493 N. If Juan slides forward and the
frictional force between the soap and the shower floor is 40 N, what is the
coefficient of friction between the soap and the floor? *
Your answer
The coefficient of friction between the soap and the floor is 0.081
If Juan steps on the soap with a force of 493 N, this is her weight, W. This weight also equals the normal reaction on the floor, N.
We know that frictional force F = μN where μ = coefficient of friction between soap and floor.
So, μ = F/N
Since F = 40 N and N = W = 493 N,
μ = F/N
μ = 40 N/493 N
μ = 0.081
So, the coefficient of friction between the soap and the floor is 0.081
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WHAT IS THE VOLUME OF A 5.71 G PLASTIC CUBE THAT HAS A DENSITY OF 1.15 G/CM3
Answer:4.96[tex]cm^{3}[/tex]
Explanation: Density is [tex]\frac{Mass}{Volume}[/tex]
so you are now looking for volume.
Volume= Density x Mass so
Volume = (5.78g) x(1.15g/ [tex]cm^{3} \frac{x}{y}[/tex]) =4.96[tex]cm^{3}[/tex]
Can someone please help me
Answer:C (198 seconds)
Explanation: The cyclist makes the first lap in (180.00 - 6.00) = 174.00 seconds. The average time per lap for all three circuits is (600.00 - 6.00) = 594/3 = 198 seconds.
Please Help with Acceleration graphs
the secondary atmosphere of the earth was composed mainly of
calculate the magnitude of the effort in the given
what is the initial velocity of an object thrown straight up that takes 5 seconds to reach its highest point?
Answer:
50 [m/s].
Explanation:
1) formula is: V-V₀=g*t, where V₀ - final velocity (it is 0), V - required initial velocity, g≈10 [m/s²] and t - elapsed time.
2) according to the formula above:
V=g*t; ⇒ V=5*10=50 [m/s].
Will give brainiest if right
