Answer:
If you take A0 to be the initial sample of iodine-131, you will be left with. 12⋅A0=A02→ ... m24 hours=12.5%mo=12.5⋅10−2⋅mo
Explanation:
is that what u look for
Sample I-131 decays to 12.5% in 24.21 days.
What is half-life?Half-life, in radioactivity, is the amount of time needed for half of a radioactive sample's atomic nuclei to decay (change spontaneously into other nuclear species by emitting particles and energy), or, alternatively, the amount of time needed for a radioactive material's rate of disintegrations per second to decrease by half.
Give parameters:
Half-life of the radioactive element I-131:T = 8.07 day
It decays to 12.5% means it decays to 1/8.
According to definition of half-life,
The radioactive element I-131 decays to half in 8.07 days.
So, the radioactive element I-131 decays to 1/8 in 3×8.07 days = 24.21 days.
Hence, the radioactive element I-131 decays to12.5% in 24.21 days.
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Describe a time when you took a big risk. Tell why it was risky and what you learned about yourself.
Answer:
You have to answer this in your opinion!
Anyways, A time I took a big risk was when I decided to talk to strangers online. It was risky because the stranger was harrasing me and doing bad stuff to me online. I learned about online safety and I learned to be careful who I talk to online! :)
Explanation:
A pinball bangs against a bumper of a pinball machine with a speed of 0.9 m/s. If the ball has a mass of 0.056 kg, what is the ball's kinetic energy?
what is the total magnification of a microscope with an eyepiece magnification of 10x and an objective lens magnification of 50x quizziz
Answer:
500x
Explanation:
A microscope had an eyepiece magnification of 10x
The objective lens magnification is 50x
Therefore the total magnification can be calculated as follows
= 10 × 50
= 500x
Hence the total Magnificattion is 500x
When an object moves, where does the energy come from?
Answer:
Kinetic energy.
Explanation:
This is the energy of motion, observable as the movement of an object or subatomic particle. Every moving object and particle have kinetic energy.
A child kicks a ball horizontally with a speed of 2.8 m/s from the end of a deck that is 8.5 m high.
a. How long will the ball take to hit the ground?
Answer:
Explanation:
time =d/s
therefore, t =8.5/2.8
t=3.02s
13. Austin rode his bike 10 m/s for two minutes. How far did he travel? A. 200 meters B. 1200 meters C. 1000 meters D. 20 meters
Answer:
B. 1200
Explanation:
60 sec in one min in 2 min there will be 120 sec. 10x120=1200
What the distance between 2 particles is doubled and the force between them is quartered, what is that called
Answer:
Coulomb's law.
Explanation:
If the distance between two particles is doubled and the force between them is quartered, this is known as Coulomb's law. Coulomb presented a law in which he states that when there is increase occur in distance between two objects, the force between them is decreases so if the distance between two particles or objects is doubled so the force between them is also quartered.
A car slows from 22 m/s to 3.0 m/s at a constant rate of 2.1 m/s2. How many seconds are required before the car is traveling at a forward velocity of 3.0 m/s?
Answer: 9.05 s
Explanation: v = u +at
v = 3 m/s
u = 22 m/s
Deceleration = 2.1 m/s^2
∴ 3 = 22 - 2.1 ( t )
∴ t = 9 .05 s
A ball is thrown up into the air. Ignore air resistance. When it is rising and reaches half of its maximum height,the net force acting on it is
Answer:
The net and only force acting on the ball thrown up into the air at half of its maximum height is the weight of the ball
Explanation:
When the ball is rising in the air, the force, F, acting on it is given by the product of the mass, m × acceleration, a
The acceleration of a body thrown in the air = Gravitational acceleration = g = Constant
Therefore;
The force acting on the body thrown in the air F = Constant = m × g (downwards)
The force acting on the ball thrown up into the air at half of its maximum height = The mass of the ball × The acceleration due to gravity = The weight of the ball.
You will get the most accurate resting heart rate if you take your pulse for ___ consecutive mornings and average the number
A: 3
B: 4
C: 5
PLSS HELPPP Which is a better deal: a 2 terabyte external hard drive for $100, or a
400-gigabyte hard drive for $50?
Answer:two terabyte external hard drive for $100
Explanation:
An atom of lithium (Li) forms an ionic bond with an atom of chlorine (Cl) to form lithium chloride. How are the valence electrons of these atoms rearranged to form this bond?
A few valence electrons are shared between the atoms.
Many valence electrons are shared between the atoms.
Electrons are transferred from the chlorine atom to the lithium atom.
Electrons are transferred from the lithium atom to the chlorine atom.
Answer:
electrons are transferred from the lithium atom to the chlorine atom
Answer:
D
Explanation:
I just took the test :)
A 0.15 kg ball is moving with a velocity of
35 m/s. Find the momentum of the ball.
Answer:
5.25 kg.m/sExplanation:
The momentum of an object can be found by using the formula
momentum = mass × velocity
From the question we have
momentum = 0.15 × 35
We have the final answer as
5.25 kg.m/sHope this helps you
It takes serina 0.25 hours to drive to school. Her route is 16km long . What is serina’s average speed on her drive to school
Explanation:
distance=16km=16000m
time=0.25hours=1/4hr=15min=900sec
speed=dist./time
=16000/900=160/9=17.777m/s
speed=17.78m/s (rounded)
Answer:
64
Explanation:
Avg. speed = total distance/total time
Avg. speed= 16km/0.25h
Avg. speed= 64km/h
Which of the technologies could mostly like be found in a wearhouse
The flow of air caused by blend in the blank creates distant blank on earth surface
Question:
The flow of air caused by _____ and the Coriolis effect creates distinct _____ on Earth's surface.
Answer:
Differences in heatingWind patternsExplanation:
The flow of air caused by variations in the rate at which the different parts are heated up as well as the Coriolis effect combine to create distinct wind patterns on Earth's surface.
The Coriolis Effect is used to describe a "force" that causes things (like objects, planes, air currents) traveling long distances around the Earth to appear to bend as they move rather than in a straight line.
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At a sports event, the car starts from iosi, in 5.0 siis acceleration is 5.
Calculate the distance travelled by ban
100 m
25 m
63 m
O bag 6.
The Score Tower hingga laglomery 4
werissa 13
Question:
At a sports event, the car starts from rest. in 5.0 s its acceleration is 5.0 m/s2. Calculate the distance travelled by car.
Answer:
62.5 metres
Explanation:
Given
[tex]u = 0[/tex] -- Initial Velocity
[tex]a = 5.0m/s^2[/tex] --- acceleration
[tex]t =5.0s[/tex] -- time
Required
Calculate the distance
This question will be solved using the following equation of motion
[tex]S = ut + \frac{1}{2}at^2[/tex]
Where S represents the distance
Substitute values for u, t and a
[tex]S = 0 * 5.0 + \frac{1}{2} * 5.0 * 5.0^2[/tex]
[tex]S = 0 + \frac{1}{2} * 5.0 * 25.0[/tex]
[tex]S = \frac{1}{2} * 5.0 * 25.0[/tex]
[tex]S = \frac{1}{2} * 125.0[/tex]
[tex]S = 62.5m[/tex]
Hence, the distance travelled is 62.5m
How are seeds different from spores?
Seeds have endosperm which provides nourishment for a new plant, but spores do not have any stored food supplies.
Spores have an endosperm and involve sperm and egg cells, while seeds do not.
Spores involve egg and sperm cells, while seeds do not.
Spores will germinate and must find good soil to survive. Seeds can survive in extremely harsh conditions.
Explanation:
1.Seeds have endosperm which provides nourishment for a new plant, but spores do not have any stored food supplies.
hope it helpful
a car travelling at 20 ms-1 accelerates uniformly for 8 s until its velocity reaches 36 ms-1.what are the acceleration and the average velocity of the car during this period
Answer:
Acceleration of the car = 2 m/s²
Average velocity of the car =28 m/s
Explanation:
Initial velocity = 20 m/s
Final velocity = 36 m/s
Time taken = 8 s
Acceleration = Δ velocity / time taken
Acceleration = 36-20 / 8 = 16/8 = 2 m/s²
Average velocity of the car =[ Initial velocity + Final velocity ] /2
Average velocity of the car = [ 20+36] / 2 = 28 m/s
What would the mechanical advantage of a ramp be if the length is 25 feet and the height is 5 feet?
10
125
5
30
Answer:
5.
Explanation:
From the question given above, the following data were obtained:
Length (L) of ramp = 25 feet
Height (H) of ramp = 5 feet
Mechanical advantage (MA) of ramp =?
Mechanical advantage of an inclined plane is simply defined as the ratio of the length of the ramp to the height of the ramp. Mathematically, it is expressed as:
Mechanical advantage = length /height
MA = L/H
With the above formula, we can simply calculate the mechanical advantage of the ramp as follow:
Length (L) of ramp = 25 feet
Height (H) of ramp = 5 feet
Mechanical advantage (MA) of ramp =.?
MA = 25 / 5
MA = 5
The, the mechanical advantage of the ramp is 5.
Answer:
5.
Explanation:
From the question given above, the following data were obtained:
Length (L) of ramp = 25 feet
Height (H) of ramp = 5 feet
Mechanical advantage (MA) of ramp =?
Mechanical advantage of an inclined plane is simply defined as the ratio of the length of the ramp to the height of the ramp. Mathematically, it is expressed as:
Mechanical advantage = length /height
MA = L/H
With the above formula, we can simply calculate the mechanical advantage of the ramp as follow:
Length (L) of ramp = 25 feet
Height (H) of ramp = 5 feet
Mechanical advantage (MA) of ramp =.?
MA = 25 / 5
MA = 5
The, the mechanical advantage of the ramp is 5.
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Please define the prefixes hyper-, hypo-, & iso- AND describe a solution that is hypertonic, hypotonic, & isotonic as well as compare how a living cell reacts when placed in a solution of each of the 3 types.
If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, there is no net water movement, so there is no change in the size of the cell. When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.
What is the momentum of a 70 kg man who is running with a velocity of 2.5 m/s?
Answer:
175kg.m/s
Explanation:
Momentum= mv 70kg*2.5m/s
help pls i need this right now
Answer:
C = - 1.625 i + 6.06 j
Explanation:
Positive angles are measured counterclockwise.
Positive angles are measured counterclockwise. To determine the component on the x axis we use the cosine of the angle while to determine the component on the y axis we use the sine of the angle.
[tex]C_{x}=6.28*cos(105)=-1.625\\C_{y}=6.28*sin(105)=6.06\\[/tex]
C = - 1.625 i + 6.06 j
For many years the posted highway speed limit was 88.5 km/h but in recent years some rural stretches of highway have increased their speed limit to 104.6 km/h. In Maine the distance from Portland to Bangor is 215 km. How much time can be saved in making this trip at the new speed limit?
Answer:
Time Saved = 0.374 h = 22.4 min
Explanation:
First we calculate the time required at old speed limit:
s = v₁t₁
where,
s = distance from Portland to Bangor = 215 km
v₁ = old speed limit = 88.5 km/h
t₁ = time taken with old speed limit = ?
Therefore,
215 km = 88.5 km/h (t₁)
t₁ = (215 km)/(88.5 km/h)
t₁ = 2.429 h
Now, we calculate the time taken at the new speed limit:
s = v₂t₂
where,
s = distance from Portland to Bangor = 215 km
v₂ = new speed limit = 104.6 km/h
t₂ = time taken with new speed limit = ?
Therefore,
215 km = 104.6 km/h (t₂)
t₂ = (215 km)/(104.6 km/h)
t₂ = 2.055 h
So, the time saved will be:
Time Saved = t₁ - t₂ = 2.429 h - 2.055 h
Time Saved = 0.374 h = 22.4 min
If you run North for 5 meters and then East for 15 meters and then
South for 2 meters all in 22 seconds. What was your speed?
0 points
Answer:
1m/s
Explanation:
D = 22m
T = 22s
S = 22÷22
= 1 m/s
A 81.9 kg person stands on her toes. The surface area of her toes in contact with the ground is only .002^ - m ^2. How much pressure is exerted between her toes and the ground, IN ATMOSPHERES ?
Answer:
3.77202
Explanation:81.9 kg×9.8N/kg÷0.0021 Pa ×(1atm/101325)=3.77202
The pressure exerted between her toes and the ground is 3.77 atm.
What is pressure?The stress at a location within a confined fluid or the perpendicular force per unit area are the two definitions of pressure used in the physical sciences. A 42-pound box with an area of 84 square inches at the bottom will apply pressure on a surface equal to the force divided by the surface area.
Given:
An 81.9 kg person stands on her toes. The surface area of her toes in contact with the ground is only 0.00210 m²,
Calculate the pressure on the toe as shown below,
The pressure on the toe = Force of man / area of toe
The pressure on the toe = mass of man × 9.8 / 0.00210
The pressure on the toe = 81.9 × 9.8 / 0.00210
The pressure on the toe = 802.62 / 0.00210
The pressure on the toe = 382200 N/m²
The pressure on the toe = 382200 / 101325 (1 atm = 101325 N / m²)
The pressure on the toe = 3.77 atm,
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Please define the prefixes hyper-, hypo-, & iso- AND describe a solution that is hypertonic, hypotonic, & isotonic as well as compare how a living cell reacts when placed in a solution of each of the 3 types.
Answer:
Hypertonic, isotonic, and hypotonic solutions and their effect on cells. ... There are some different explanations out there. ... Tonicity is a concern for all living things, particularly those that lack rigid cell walls and live in ...
What travels by vibrating particles? Mechincal Waves or ElecrtoMagnetic Waves.
Answer:mechanical waves.
Explanation:
Mechanical waves require the particles of the medium to vibrate in order for energy to be transferred. For example, water waves, earthquake/seismic waves, sound waves, and the waves that travel down a rope or spring are also mechanical waves.
While delivering 125 kg blocks of ice to a local village, Kristoff and his family (and Sven too) come upon a cliff that is 5.7 m above them. To solve their problem, they build a catapult that will launch their blocks of ice with an initial velocity of 15 m/s and at an angle of 45 degrees above the ground.
Prove that the catapult will successfully launch the ice blocks up to the top of the cliff. Quantities you will need to solve for will be initial vertical velocity, horizontal velocity, the distance the catapult is from the cliff, and the amount of time it takes the ice to reach the cliff. Assume that they are experts and have arranged everything so that the ice blocks just barely reach the top of their parabolic path when they land at the top of the cliff and make a smooth landing. Draw a picture of the scene to help you visualize what is happening.
After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
What is the rate of acceleration while the blocks slow to a stop?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
How long do the blocks take to slow to a stop?
What is the amount of friction between the ice and the snowy ground?
Answer:
a. Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
b. -2.81 m/s²
c. 3.78 s
d. -351.25 N
Explanation:
a. After landing on the flat land above, each block of ice travels 20 meters while slowing to a stop.
For the block of ice to reach the top of the cliff, its maximum height, h should be greater than or equal to 5.7 m. That is, h ≥ 5.7 m.
The maximum height of a projection h, projected with an initial velocity v at an angle Ф is h = v²sin²Ф/2g where g = acceleration due to gravity = 9.8 m/s².
For the block of ice, v = 15 m/s and Ф = 45°. So,
h = v²sin²Ф/2g
= (15 m/s)²sin²45/(2 × 9.8 m/s²)
= 225 (m/s)²(1/√2)²/19.6 m/s²
= 225 (m/s)²(1/2)/19.6 m/s²
= 112.5 (m/s)²/19.6 m/s²
= 5.74 m
Since h = 5.74 m > 5.7 m, the height of the cliff, the block of ice will successfully launch to the top of the cliff.
The graph is in the attachment.
b. What is the rate of acceleration while the blocks slow to a stop?
Using v² = u² + 2as where u = initial horizontal velocity of block = 15m/scos45° = 10.61 m/s, v = final velocity of block = 0 m/s since it stops, a = acceleration and s = distance block moves = 20 m
So, a = (v² - u²)/2s
substituting the variables into the equation, we have
a = ((0 m/s)² - (10.61 m/s)²)/2(20 m)
= - 112.57 (m/s)²)/40 m
= -2.81 m/s²
c. How long do the blocks take to slow to a stop?
Using v = u + at where u = initial horizontal velocity of block = 10.61 m/s v = final velocity of block = 0 m/s since it stops, a = acceleration = -2.81 m/s² and t = time it takes block of ice to stop
So, making t subject of the formula,
t = (v - u)/a
substituting the values of the variables, we have
t = ( 0 m/s - 10.61 m/s)/-2.81 m/s²
= -10.61 m/s/-2.81 m/s²
= 3.78 s
d. What is the amount of friction between the ice and the snowy ground?
The frictional force, f = net force on block of ice
f = ma where m = mass of bock = 125 kg and a = acceleration of block = -2.81 m/s²
f = ma
= 125 kg(2.81 m/s²)
= -351.25 N
how to create or build a homemade golf club. is this possible? If so, what suggestion did you find? Do you have an original idea on how to build a homemade golf club? what types of materials and tools would you need? what skills are necessary to construct the club?
Answer:
All you need is golfing equipment make a small hole in the ground and have like something to cover the sun off of you and boom you got a golfing spot and a golf club no skills needed. Oh and you need a small flag for your gold hole but then your good and you can have fun
Explanation: