Final answer:
Using the conservation of momentum, the final speed of the boy after throwing the pumpkin is 0.7467 m/s to the left, and the final speed of the girl after catching the pumpkin is 0.6857 m/s to the right.
Explanation:
The problem you're trying to solve involves the conservation of momentum, because momentum is conserved when objects interact in a closed system without external forces, such as the scene described with skaters on ice. To find the final speeds of the boy and the girl, we'll use the principle of conservation of linear momentum. Since initially they are both at rest and the boy throws the pumpkin, the final momentum of the system must be zero.
Using the equation for conservation of momentum: momentum before the throw = momentum after the throw. Initially, both the boy and the pumpkin are stationary, so their initial combined momentum is 0. After the boy throws the pumpkin, he will move in the opposite direction to conserve momentum.
Momentum of the boy after the throw: m_boy × v_boy = 0 - (mass of pumpkin × velocity of pumpkin)
Momentum of the girl after catching the pumpkin: m_girl + mass of pumpkin × v_girl = mass of pumpkin × velocity of pumpkin
m_boy = 45kg (mass of the boy)
m_pumpkin = 12kg (mass of the pumpkin)
v_pumpkin_initial = 2.8 m/s (speed of the pumpkin)
Let's calculate the speed of the boy after he throws the pumpkin:
45kg × v_boy = 0 - (12kg × 2.8 m/s)
v_boy = (-33.6 kg×m/s) / 45kg
v_boy = -0.7467 m/s
The negative sign indicates that the boy is moving in the opposite direction to the pumpkin's initial movement. Now, let's find the speed of the girl after catching the pumpkin:
(37kg + 12kg) × v_girl = 12kg × 2.8 m/s
49kg × v_girl = 33.6 kg×m/s
v_girl = 0.6857 m/s
The boy's final speed is 0.7467 m/s to the left, and the girl's final speed is 0.6857 m/s to the right.
To determine a waves' frequency, you must know the
A. distance it travels.
B. number of oscillations in a given period of time.
C. distance between the crest and trough.
D.height of the wave.
Answer : Frequency equals number of oscillations in a given period of time.
Explanation :
The number of oscillations in a given period of time is known as the frequency of the wave. It is denoted by [tex]\nu[/tex]. Its SI unit is hertz (Hz).
It is also defined as the inverse of time period i.e.
[tex]\nu=\dfrac{1}{T}[/tex]
T is the time period.
Hence, the correct option is (B) " number of oscillations in a given period of time ".
PLEASE HELP ASAP WILL GIVE BRAINLIEST <333
Answer 1) For calculating ΔU;
We can use the expression for the first law of thermodynamics which is,
ΔU = Q + W
Where ΔU is the Change in internal energy, Q is heat added to the system and W is the work done on the system.
As, Q = + 51 KJ and W = -15 KJ.
So, ΔU = 51 -15 = 36 KJ.
Hence, ΔU = 36 KJ
Answer 2) Using the same first law of thermodynamic equation for calculating ΔU (Internal Energy o the system) ;
ΔU = Q + W;
Given, Q = + 100 KJ and W = - 65 KJ
On substituting the values in the above equation we get,
ΔU = 100 - 65 = 35 KJ
Therefore, ΔU = 35 KJ
Answer 3) Using the same first law of thermodynamic equation for calculating ΔU (Internal Energy o the system) ;
ΔU = Q + W;
Given here, Q = - 65 KJ and W = - 20 KJ
On substituting the above values in the equation we get,
ΔU = -65 -20 = - 85 KJ
Therefore, ΔU = - 85 KJ for this system.
Answer 4) According to the answers in 1), 2) and 3) it can be seen that there has been change in the internal energies of the system for all, but some are positive changes and some are negative.
As per the definition of the internal energy, when the system does work on its surroundings, energy is found to be lost, and E is observed to be negative; and when the surroundings do work on the system, the internal energy of the system becomes larger, converting E into positive.
So, it is clear that in case 3) the system did work on the surroundings as E value is found to be negative, rest have positive E values.
If the earth’s gravity were much less powerful our atmosphere would be similar to
what does it mean to say that momentum is conserved
20 POINTS AND BRAINLIEST
describe the forces acting on the ball at the instant it is pushed. Do these forces continue to act on the ball as it rolls
describe the shapes of a concave lens and a convex lens
why is it important foe scientists to know how many valence electrons a given element has
What is the role of the respiratory system?
a.
to bring water into the body
b.
to bring oxygen into the body
c.
to bring carbon dioxide into the body
d.
none of the above
A television of mass 13 kg sits on a shelf. What is the normal force acting on the television?
A. 13.0 N
B. 127 N
C. 51.2 N
D. 99.4 N
Answer:
Normal force, F = 127 N
Explanation:
It is given that,
Mass of the television, m = 13 kg
It is sitting on the shelf. We have to find the normal force acting on it. The forces acting on it are normal force and its weight. So, the normal force is given by :
F = mg
g = acceleration due to gravity
[tex]N=13\ kg\times 9.8\ m/s^2[/tex]
F = 127.4 Newton
or
F = 127 N
Hence, the normal force acting on the television is 127 N
Explain what happens to the pitch of a cell phone ringing when the amplitude of a sound wave increases.
the pitch of the cell phone ringing will remains same when the amplitude of a sound wave increases.
The pitch of a sound wave depends on its frequency. more frequency means higher pitch and less frequency means lower pitch. The amplitude of wave is the maximum displacement of the particles of the medium from their mean positions. Increase in amplitude will increase the loudness and not the pitch. So the pitch remains same as the amplitude of sound wave is increased.
Technician A says that the burning of the air-and-fuel mixture in the cylinder is called fuel activation. Technician B says that the basic function of the upper-end components is to control the flow of air-and-fuel mixture into the engine and the flow of exhaust gases out of the engine after combustion. Who is right? A. Both Technicians A and B B. Technician A only C. Neither Technician A nor B D. Technician B only
How this answer can be Verifies if it's wrong!?!?!
If a forklift raises a 76-kg load a distance of 2.5 m, about how much work has it done?
Final answer:
To calculate the work done by the forklift, we need to find the force exerted by the forklift and multiply it by the distance it raises the load. The force exerted by the forklift can be found using the formula Force = mass x gravity. The work done by the forklift is approximately 1864 Joules.
Explanation:
To calculate the work done by the forklift, we can use the formula:
Work = Force x Distance
First, we need to find the force exerted by the forklift. Since the load has a mass of 76 kg, we can use the formula:
Force = mass x gravity
where gravity is approximately 9.8 m/s^2 (acceleration due to gravity). So, the force exerted by the forklift is:
Force = 76 kg x 9.8 m/s^2 = 745.6 N
Now, we can calculate the work done by the forklift:
Work = 745.6 N x 2.5 m = 1864 J
Therefore, the forklift has done approximately 1864 Joules of work.
An object's mass is a measure of how much matter makes it up. An object's weight is a measure of the gravitational force that acts on it. An object's mass is always _______ its weight.
A. proportional to
B. equal to
C. half of
D. double
An object's mass is proportional to its weight. So the correct answer would be an option (A) proportional to.
What are fundamental forces?At the considerable fundamental level, all the forces in the existence (as currently understood) are emanated from only four forces:
The gravitational force
The electromagnetic force
The weak nuclear force
The strong nuclear force
An object's mass is proportional to its weight because weight is determined by the gravitational force acting on an object, which is directly proportional to the object's mass.
Specifically, an object's weight is equal to its mass multiplied by the acceleration due to gravity.
Therefore, if the mass of an object increases, its weight will increase proportionally, and if the mass decreases, the weight will decrease proportionally as well.
Therefore, the correct answer would be option (A) proportional to.
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which has a higher acceleration:a 10kg object acted upon with a net force of 20N or an 18kg object acted on by a net force of 20N
Explanation:
The expression of the applied force in terms of mass and acceleration by using Newton's second law is as follows;
F= ma
Here, m is the mass of the object and a is the acceleration of the object.
Calculate the acceleration of a 10 kg object acted upon with net force of 20 N in the above expression.
Put m= 10 kg and F= 20 N in the above expression.
20= (10)a
a= 2 m/s^2
Calculate the acceleration of a 18 kg object acted upon with net force of 20 N in the above expression.
Put m= 18 kg and F= 20 N.
20= (18)a
a= 1.11 m/s^2
Therefore, the acceleration of a 10 kg object acted upon with net force of 20 N is greater than the acceleration of a 18 kg object acted upon with net force of 20 N.
Darrell is trying to remove a nail from a board using the claw of a hammer, but the nail is stuck. Which of the following could Darrell do to make the job easier?
A.
Use a hammer with a longer handle.
B.
Use a heavier hammer.
C.
Use a hammer with a shorter handle.
D.
Use a hammer with a sharper claw.
It's C loves! I just got it right.
Answer: The answer is c
Suppose you increase your walking speed from 6 m/s to 14 m/s in a period of 1 s. What is your acceleration?
The horseshoe crab looks very similar to its fossil ancestor from the Jurassic era. Why has the horseshoe crab not evolved?
A. Its original form always remained well adapted to its environment.
B. The species was affected by natural selection.
C. The species did not pass on genetic information to its offspring.
D. The species underwent major mutations in a short period of time.
The answer is A. Natural selection always favors individuals in a population that are well adapted to their environment. These individuals are able to get to maturity and pass down their genes to subsequent generations. Any disadvantages mutations in the population are eliminated by natural selection.
Answer:
its a
A. Its original form always remained well adapted to its environment.
because it takes time to adapt to a new place
Explain why Earth and other planets were not solid when they formed during the beginning of the Precambrian, approximately 4,600 million years ago (MYA). What was this particular time period called, and why is this time period not really considered apart of Earth’s geological history?
Please help
I'll mark who ever comes up with the best answer brainliest
if a glacier is in equilibrium, where ablation is equal to the accumulation, what occurs in the terminus or 'snout'
If a glacier is in equilibrium, its terminus remains stable as ice loss from ablation equals ice gain from accumulation. The glacier's terminus does not advance or retreat under these conditions.
If a glacier is in equilibrium, it means that the ablation (loss of ice) is equal to the accumulation (gain of ice). The point where this balance is achieved is the equilibrium line. If the glacier is in equilibrium, the terminus or 'snout' of the glacier remains at a stable position. While the ice continues to flow downslope, the position of the terminus does not advance or retreat because the amount of ice being lost to ablation is equal to the amount being gained through accumulation.
Which tubes will test positive for Benedict's test and which will test positive for Iodine test?
Benedict's test is used to identify reducing sugars and results in color changes from blue to green, yellow, or red. The Iodine test, on the other hand, identifies starch by changing from a brown iodine color to a blue-black color.
Explanation:In conducting laboratory tests, two popular assays are the Benedict's test and the Iodine test. The Benedict's test is used to detect the presence of reducing sugars, like glucose, in a sample. If a tube turns from blue (the color of the original Benedict's solution) to green, yellow or red, it indicates a positive result - the various colors represent different levels of sugar concentration.
Conversely, the Iodine test is used to detect the presence of starch in a sample, such as in a potato or bread. In a positive Iodine test result, the originally brown iodine solution will change to a blue-black color upon interaction with starch.
Therefore, tubes containing reducing sugars (like glucose or lactose) will test positive in a Benedict's test, and tubes containing starch will test positive in an Iodine test.
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In what way do acids affect your body?
Which of the following statements is true?
A.Animals add water vapor to the air through respiration.
B.Plants add water vapor to the air through photosynthesis.
C.Both plants and animals can make protein using nitrogen compounds.
D.Automobiles are the leading cause of acid rain.
If it takes 320 N of force to push a box up a ramp, yet it would take 1,600 N of force to lift the box straight up, what is the mechanical advantage of the ramp? O A. 0.2 O B. 4 O C. 5 O D. 40
Which of the following materials is a conductor of electric current? a wooden spoon,a plastic game piece,a glass window,a copper wire
its a copper penny hope this helps
Please need help still lost on this
A longitudinal wave is a wave that vibrates in the same direction as its direction of propagation. In a longitudinal wave, the direction of particle displacement is parallel to the direction of wave motion. The correct answer is "In a longitudinal wave, particle displacement is parallel to the direction of wave motion."
This means that as the wave moves forward, the particles of the medium through which the wave travels move back and forth along the same line as the wave's direction of propagation. This type of wave is often referred to as a compressional wave because it causes the particles of the medium to be compressed and then expanded as the wave passes through. An example of a longitudinal wave is sound waves. These waves move through the air by compressing and expanding the air particles along the same direction as the wave's motion, producing changes in air pressure that our ears detect as sound. Therefore, the correct answer is "In a longitudinal wave, particle displacement is parallel to the direction of wave motion."For more questions on longitudinal wave
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What is the difference between a constellation and an “asterism”? Name at least one commonly known asterism.
A constellation is a sector into which the sky is divided, while an asterism is a noticeable star pattern within a constellation. The Big Dipper is a commonly known asterism within the constellation of Ursa Major.
Explanation:A constellation is one of the 88 sectors into which the sky is divided. Each point in the sky falls within a specific constellation. On the other hand, an asterism is an especially noticeable star pattern within a constellation. The Big Dipper, which is an asterism within the constellation of Ursa Major, is a commonly known example.
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When sunlight strikes oil on the surface of water, a variety of colors are observed. What is the best explanation for this observation?
if a swimmer pushes off a pool wall with a force of 250n, what is her acceleration.
What is an ion found in a glass of water
Answer:
[tex]H^{+}[/tex] ion and [tex]OH^{-}[/tex] ions.
Explanation:
As we notice the glass of water, in this observation we find that the glass also made up of sodium silicate which will give us oxygen ion.
And the water which is present in the glass will break into the hydroxyl ion and [tex]H^{+}[/tex] ion .
Therefore, glass of water contains [tex]H^{+}[/tex] ion and [tex]OH^{-}[/tex] ions.
An ion commonly found in a glass of water is the hydrogen ion (H+).
How does this happen?When water molecules dissociate, a small fraction of them break apart into hydrogen ions (H+) and hydroxide ions (OH-). These ions are responsible for the water's ability to conduct electricity.
The presence of hydrogen ions in water makes it slightly acidic, with a pH below 7. However, the concentration of hydrogen ions in pure water is very low, making it close to neutral on the pH scale. The balance of these ions is essential for maintaining the pH and chemical properties of water.
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A .5 kg toy train car moving forward at 3 m/s collides with and sticks to a .8 kg toy car that is traveling at 2 m/s what is the final velocity of the two cars round to the nearest 10th