Hope it helps.
Do comment if you have any query.
A sample of polonium-210 was left for 414 days.
BA
After this time it had a mass of 1.45 x 10^-4 g
The half-life of polonium-210 is 138 days.
Calculate the initial mass of the sample
Answer:
PO(1) = PO(0) / 2 1 refers to 1 half life of PO(0)
PO(2) = PO(1) / 2 = P(0) / 4 amount of PO left after 2 half-lives
PO(3) = PO(2) / 2 = PO(0) / 8 amount of PO left after 3 half-lives
414 da / 138 da = 3 3 half-lives pass in 414 da
PO(0) = 8 PO(3) = 8 * 1.45E-4 g = 1.16E-3 g = .00116 g after 414 days
A 455 kg cannon fires a 21 kg cannonball at 26 m/s. If the cannon is on wheels, at what velocity does it move backward?
Answer:
A cannon ball of mass 4.0 kg is fired from a stationary 96 kg cannon at 120 m/s. Calculate the velocity of the cannon immediately after firing.
total momentum of cannon and cannon ball before = 0 kg m/s - because neither object is moving
total momentum of cannon and cannon ball after collision = 0 kg m/s - because momentum is conserved
Momentum of cannon ball after firing = 4.0 × 120 = 480 kg m/s.
Momentum of cannon after firing = -480 kg m/s (because it recoils in the opposite direction and 480 - 480 = 0 kg m/s, the total momentum after collision).
Rearrange p = m v to find v:
v = p/m
v = 480 divided by 96
v = 5.0 m/s
Note that the forward velocity of the cannon ball was given a positive value. The negative value for the cannon's velocity shows that it moved in the opposite direction.
Can anyone tell the answer
A boy drops a stone in a well and finds it takes 2.60 seconds to hit the water.
A) How deep is the well?
B) With what speed does the stone hit the water?
Answer:
(i) How deep is the well (Height)
=> t = √(2H/g)
=> √2H = t × g
=> 2H = t² × g²
=> 2H = (2.60)² × (10)²
=> 2H = 6.76 × 100
=> 2H = 676
=> H = 676 ÷ 2
=> H = 338 m
(ii) speed of the stone:
=> v = √(2Hg)
=> v = √(2 × 338 × 10)
=> v = √6760
=> v = 26√10 m/s
what do you mean by frequency of sound is 50Hz
Answer:
This means the source of sound vibrates 50 times in one second. Therefore, number of vibrations in 1 minute, i.e. in 60 seconds = 50 x 60 = 3000 times.
Explanation:
The trachea splits into two branches called larynx true or false
pls answer somebodyyyyyyy
Answer:
False
Explanation:
The trachea divides into left and right air tubes called bronchi, which connect to the lungs. Within the lungs, the bronchi branch into smaller bronchi and even smaller tubes called bronchioles.
Hope this helps :)
compared to ultraviolet waves, the wavelength of infrared waves is
Answer:
Visible spectrum is considered to be:
4000-7000 Angstroms
400 -700 Microns
Ultraviolet is <400 microns causes sunburn, cellular damage
Infrared >700 microns -heating, heat lamps, etc
The total power input to the leaf blower is 750 W. The useful power outlet of the leaf blower is 360 W. Calculate the efficiency of the leaf blower.
H = Pu / P x 100% = 360/750 x 100% = 48%
P/s: Pu is the useful power outlet of the leaf blower
P is the total power input to the leaf blower
ok done. Thank to me :>
how much of the light that reaches the earth from the sun is used for photosynthesis
Answer:
Less than one percent of the total energy that reaches Earth is used by plants for photosynthesis
Which of the following is a force?
1) inertia
2) friction
3) acceleration
4) velocity
Hi there!
[tex]\large\boxed{\text{Friction.}}[/tex]
We can go through each:
1) Inertia is NOT a force. Inertia is defined as an object's resistance to motion, or its mass.
2) Friction IS a force because it results in acceleration.
3) Acceleration is not a force, but rather a product of force.
4) Velocity is simply a quantity that can be changed as a result of a force.
The magnetic field of a straight, current-carrying wire is:
Explain the relationship between the frequency, energy, and wavelength of a wave.
Answer:
Explanation:
The energy equation is E=hv
Consider the dot diagrams for Objects A, B, and C. The arrow-
represents the direction of motion. Match the motion of
Objects A, B, and C to one of the lines on the graph.
Numbers can be used only one time.
A
2
B
Pos'n
3
С
-t
Tap
A matches graph:
B matches graph:
C matches graph:
4
5
6
--
Pos'n
t
Seismic waves do not travel along the Earth’s surface.
Please select the best answer from the choices provided
T (true)
F (false)
Both choices are correct.
Some seismic waves travel along the Earth's surface.
Others don't.
Answer:
False
Explanation:
Edge2022
Which of the following, if eliminated, would completely prevent the greenhouse effect from occurring on earth?
A. Atmosphere Clouds
B. Fossil fuels
C. Acid rain
D. The ozone layer
E. Chlorofluorocarbons
Chlorofluorocarbons is eliminated, would completely prevent the greenhouse effect from occurring on earth.
What is greenhouse effect?The greenhouse effect is a phenomenon in which heat from a planet's host star passes through its atmosphere and warms the surface of the planet, but greenhouse gases in the atmosphere prevent part of the heat from going directly to space, making the world warmer.
Chlorofluorocarbons gas is main cause of greenhouse effect so when we remove it from atmosphere than green house effect will be reduced.
Chlorofluorocarbons is eliminated, would completely prevent the greenhouse effect from occurring on earth.
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Managers use information systems to help them make decisions that will improve their businesses. What three levels of information do managers need to make these decisions? Provide one example of how information systems can provide this data.
The main categories of information systems include management-level system, operational-level system, and strategic-level system.
Information system simply means the integrated set of components that are vital for the collection, storage, and processing of data to make organizational decisions.
Information systems can be used at operational level in order to provide data that can support operational activities by keeping track of the transactions of the company.
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An element with a force of 0.00SN moves at a minimum: 0.2m / s². Calculate the mass of that element.
Please find attached photograph for your answer.
Hope it helps.
Do comment if you have any query.
A ball is thrown at an angle of 38 degrees to the horizontal. What happens to the magnitude of the ball's vertical acceleration during the total time interval that the ball is in the air
Answer:
I belive it is 38 degrees
Explanation:
The magnitude of the vertical acceleration of the ball during the total time interval that the ball is in the air, the acceleration remains the same.
What is projectile motion?A projectile can be defined as an object that is in flight after being projected. The acceleration acting in the vertical direction which is because of gravity in a projectile motion. Therefore, we can apply the equations of motion separately on X-axis and Y-axis to find the parameters.
If any projectile is projected with the velocity 'v' and is making an angle θ from horizontal. The horizontal component of the initial velocity of the projectile will be equal to vcosθ.
The vertical component of the initial velocity of the projectile is v sinθ. The horizontal component remains the same as no acceleration is acting horizontally.
The ball will experience only one force which is gravity if there is no air resistance. The gravity remains constant if there is no initial speed of the ball. The acceleration of the ball will be in the downward direction and stays constant.
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A science student observes three lines in an emission spectrum, one red, one yellow, and one blue. Which one was caused by an electron jumping the shortest distance
The transition that produced red light was caused by an electron jumping the shortest distance.
Visible light is made up of seven wavelengths the magnitude of the wavelength of a transition reflects the energy associated with such transition. The longer the wavelength shorter the transition that produced it.
Given that three lines in the visible spectrum produced three lines as follows;
Red - 625 - 740 nm
Yellow - 565 - 590 nm
Blue - 445 - 520 nm
We can see that the longest wavelength corresponds to red light hence it was caused by an electron jumping the shortest distance.
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A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 20 s. It is then turned off and coasts to a stop in an additional 40 s. In the one minute of rotation, through how many revolutions did the fan turn?.
Hi there!
We can first find the angular displacement of the first 20 seconds by finding the angular acceleration.
Begin by converting 120 rev/min to rev/sec:
120 rev/min × 1 min/60 sec = 2 rev/sec
ω = αt
2 = 20α
α = 0.1 rev/sec²
θ = ωit + 1/2αt²
The fan starts from rest, so:
θ = 1/2αt²
θ = 1/2(0.1)(20²) = 20 revolutions
Now, for the next 40 seconds, we can find the fan's deceleration:
ωf = ωi + αt
0 = 2 + αt
-2 = 40α
α = -0.05 rad/sec²
Use the above equation:
θ = ωit + 1/2αt²
θ = 2(40) + 1/2(-0.05)(40²) = 80 - 40 = 40 rev
θ = 4800 - 2400 = 2400 revolutions
Add the two:
θtotal = 20 + 40 = 60 revolutions
6. Two skaters, Jim (65 kg) and Mary (50 kg) are standing at rest on the ice. They push each other
and Mary recedes at 2.5 m/s towards the east. Find Jim's velocity (magnitude and direction).
Hi there!
This is an example of a recoil collision.
Let m1, v1 be Mary
Let m2, v2 be Jim
Utilize the conservation of momentum:
m1v1 + m2v2 = m1v1' + m2v2'
The initial velocities are zero (at rest), so:
0 = m1v1' + m2v2'
Let east be positive, so Jim recoils with a negative velocity:
0 = m1v1' - m2v2'
Set the two equal and solve:
m1v1' = m2v2'
m1v1'/m2 = v2'
(50)(2.5)/65 = v2' = 1.92 m/s to the WEST
Select the correct answer.
When rocks containing copper are oxidized, they tend to turn from red to green. Based on this information, what evidence
would best support the theory that oxidation could not have occurred in Earth's early atmosphere?
Rocks from early Earth that contained copper are green in color.
There are no copper-containing rocks from early Earth.
Rocks from early Earth that contained copper are red in color.
All copper minerals were converted to iron minerals.
Answer:
Rocks from early Earth that contained copper are red in color
Explanation:
"Copper, a red mineral, reacts with oxygen to form a green-colored compound. In early years, rocks containing copper were red. This fact shows that there was no oxygen in the early atmosphere to oxidize red copper into the green-colored compound."
A 45 kg object has a momentum of 255 kg m/s northward.What is the objects velocity
Answer:
5.66 m/s
Explanation:
p=mv
255 = 45v
v = 255/45
v = 5.66 m/s
If you want to verify your answer, just insert your value to the equation.
1 =
Q=240c
t=300s
Please explain Im so confused
Answer:
Answer:
0.8 A
Explanation:
Given: Q = 240 C
t = 300 s
Required: I
Equation: I = Q / t
Solution: I = 240 C / 300 s
Answer: I = 0.8 A
A race car is traveling at a speed of 80. 0 m/s on a circular racetrack of radius 450 m. What is it's centripetal acceleration in m/s2?.
Answer:
14.2m/s^2
Explanation:
The centripetal acceleration of the race car is 14.22 m/s².
What is centripetal acceleration?Centripetal acceleration is a characteristic of an object's motion along a circular path. Centripetal acceleration applies to any item travelling in a circle with an acceleration vector pointing in the direction of the circle's center.
In your daily existence, you must have encountered numerous instances of centripetal acceleration. A centripetal acceleration occurs when you drive in a circle, and a centripetal acceleration also occurs when a satellite orbits the earth. Centripetal refers to being in the center.
Given that: Speed of the race car: v = 80.0 meter/second.
Radius of the racetrack: r = 450 meter.
Hence, the centripetal acceleration of the car is = v²/r
= (80.0)²/450 m/s²
= 14.22 m/s².
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What do you notice about the lines of earthquakes and volcanoes and where they seem to occur on Earth's surface?
Answer:
Most earthquakes and volcanoes occur because of the movement of the plates, especially as plates interact at their edges or boundaries.
Explanation:
you moved from the top bunk of a bunk bed to the bottom and noticed that the air is colder. the cold air stays at the bottom because of
Answer:
heat transfer? sorry if I'm wrong!
A man on the moon with a mass of 90 kilograms weighs 146 newtons. The radius of the moon is 1.74 x 10^6
meters. Find the mass of the moon
equation- F= G m1 m2/ d^2
Answer:
7.36 × 10^22 kg
Explanation:
Answer:
D
Explanation:
If someone were to be researching and studying similarities between our sun and a neighboring star, what kind of scientific investigation would they be conducting
Answer:
a
Explanation:
because there both in the solar system
There are billions of galaxies in the universe and each contains trillions of stars which are different in size, distance from the earth, brightness etc.When we scientifically investigate about this we can obtain the stars of similarity to sun in brightness and size.
What is galaxies?Galaxies are a group of stars, dust and dark matter joined together by the force of gravitation. Three trillions of stars in each galaxies. Some stars forms a group of certain size and shape and number also they are called constellations.
Sun is the closest star to earth. Thus sunlight is the major source of energy in earth. Sunlight reaches the earth surface within a time of 8 minute and 6 seconds.
The star which nearest to sun is named proximacentory which far from the earth and we can see it as spot of light in the sky. There are many more stars which are giants are more brighter than sun.
The brightness and luminosity is determined based on the distance from the earth. Which can be calculated in terms of light years. Each star has an age and length of life. After that the star may die still their light energy can be seen in sky because their light takes more years to reach here.
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Which type of wave requires a medium?
A. Light wave
B. Electromagnetic wave
C. Sound wave
D. Ultraviolet wave
The correct answer is option C. Sound wave
A sound wave is an example of a mechanical wave which requires a medium.
Answer:
The closest is “A”, however an ocean wave is not truly a transverse wave. It belongs to the category “gravity wave” (note: NOT gravitational wave as in cosmology) and occur at the interface between two media. In the case of a wave on the ocean surface it is specifically called a “surface gravity wave” . The particles in a surface gravity wave move in an oscillatory circular motion called the wave orbit not in a back and forth motion.