Answer:
0.62
Explanation:
Ff = mg = 52 N
Since the speed is constant, the friction
force equals the force exerted by the
girl, 36 N.
Ff = ukFn
so uK = Ff/Fn
= 36 N/52 N
= 0.69
Force is needed to pull the sled across the snow at constant speed is 0.62 N
What is force?A force in physics is an effect that has the power to alter an object's motion. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Given in the question a boy exerts an unknown horizontal force as he pulls a 52 N sled across packed snow. The coefficient of friction is 0.12. If a person weighing 650 N sits on the sled,
Ff = mg = 52 N
Since the speed is constant, the friction force equals the force exerted by the boy, 36 N.
Ff = (uk).(Fn)
so uK = Ff/Fn
= 36 N/52 N
= 0.69 N
Force is needed to pull the sled across the snow at constant speed is 0.62 N
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A horizontal force acts on an object on a fric- tionless horizontal surface. If the force is halved and the mass of the object is doubled, the acceleration will be (1) four times, (2) two times, (3) one-half, (4) one-fourth as great. (b) If the acceleration of the object is , and the force on it is doubled and its mass is halved, what is the new acceleration
(a) If the force is halved and the mass of the object is doubled, the acceleration will be one-fourth as great.
(b) if the force on it is doubled and its mass is halved, the new acceleration will be four times as great.
The force on an object is determined by applying Newton's second law of motion;
F = ma
[tex]\frac{F_1}{m_1a_1} = \frac{F_2}{m_2a_2}[/tex]
(a)
when the force is halved, F₂ = 0.5F₁,
mass is doubled, m₂ = 2m₁
[tex]\frac{F_1}{m_1a_1} = \frac{0.5F_1}{2m_1a_2} \\\\2m_1a_2F_1 = 0.5F_1 m_1a_1\\\\2a_2 = 0.5a_1\\\\a_2 = \frac{0.5a_1}{2} = \frac{a_1}{2 \times 2} = \frac{a_1}{4} \\\\a_2 = \frac{1}{4} (a_1)[/tex]
Thus, If the force is halved and the mass of the object is doubled, the acceleration will be one-fourth as great.
(b)
when the force is doubled, F₂ = 2F₁,
mass is halved, m₂ = 0.5m₁
[tex]\frac{F_1}{m_1 a_1} = \frac{2F_1}{0.5m_1 a_2} \\\\0.5m_1a_2 F_1 = 2F_1m_1a_1\\\\0.5a_2 = 2a_1\\\\a_2 = \frac{2a_1}{0.5} \\\\a_2 = 4(a_1)[/tex]
Thus, if the force on it is doubled and its mass is halved, the new acceleration will be four times as great.
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a bullet with 200g of mass, moving with velocity of 600 m/s. enters to a block of wood and stops in 0.1 sec. what is the average force bullet feels?
You are at a rest stop 250 miles north of New York City. You then travel north at a constant velocity of 65 miles per hour for 2.0 hours. Describe your location relative to New York City.
NEED HELP!!!! 15 POINTS!!!!
Which BEST explains why it is important to warm up before strenuous exercise?
A.
It is very hard on the joints when exercise begins without warm up.
B.
It strains the muscles if blood and oxygen levels are not already activated.
C.
Warm-ups limit the oxygen supply, prepping the body for the rush during exercise.
D.
An exercise session should not include more than 30 minutes of aerobic activity.
Answer:
A
Explanation:
or else u would get a muscle pull
Answer:
a
Explanation:
An engineer is designing the foundation of large building and wants to be sure that movement in the ground will do as little damage to the building as possible. Which building material would be best to use in the foundation?
Steel-reinforced concrete is a better material for foundation where movement in the ground is envisaged.
The kind of material used for the foundation of a building greatly impacts the ability of that building to cope with movements in the ground such as during earthquakes.
For instance, when the foundation is made of brick or concrete which has a low ductility, these materials are incapable of absorbing a lot of energy. However, steel-reinforced concrete is a better material for foundation where movement in the ground is envisaged.
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Imagine everyone in the United States exhibited the character traits we have been discussing. In what ways would America be different?
Now imagine no one in American exhibited any of those character traits. In what ways would America be different?
Answer:
Characterization is the process by which the writer reveals the personality of a character. Characterization is revealed through direct characterization and indirect characterization. Direct Characterization tells the audience what the personality of the character is.
Explanation:
Mood, or atmosphere, is the feeling created in the reader by a literary work or passage. ... Often, a writer creates a mood at the beginning of a work and then sustains the mood throughout. Sometimes, however, the mood of the work changes dramatically.
Describe how energy is transferred from 1 form to another
Answer:
Thermal energy may be transferred in three ways: conduction, convection, and radiation. Conduction occurs when heat energy is exchanged between nearby molecules that are in touch with one another.
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Describe how a roller coaster works in terms of using potential energy and kinetic energy:
Answer:
Traditionally, the coaster cars are pulled up the first hill by a chain; as the cars climb, they gain potential energy. Then, when the cars descend this hill, potential energy is again changed to kinetic energy. This conversion between potential and kinetic energy continues throughout the ride.
Explanation: hi how ya doing
a spring vibrates 120 times in 2 mins find its frequency and time period
2 minutes is 120 seconds, so if you were finding vibrations per minute, it would be 60 times a minute.
As a falling apple, approaches the ground, its potential energy
Answer:
Decreases.
Explanation:
When an object with potential energy falls to the ground, its potential energy decreases and kinetic energy increases.
vector u has a magnitude of 20 and direction of 0°.vector v has amagnitude of 40and a direction of 60°.find the magnitude and direction of the resultant
Addition of vectors:
vector u
has a magnitude of 20 and a direction of 0º with respect to the horizontal, vector v has a magnitude of 40 and a direction of 60º with respect to the horizontal.
a) Find the magnitude and direction of the resultant to the nearest whole
number.
Vector Sum:
The resultant of two vectors is simply the vector sum of the vectors. There are a handful of ways to present the resultant factor; the notation that shows the vector magnitude and direction is called the polar vector notation. An example of a vector presented in polar vector notation is
a∠θ where a is the magnitude and θis the angle that the vector makes with the horizontal axis.
Answer and Explanation:
Let's first present the vectors in rectangular vector notation.
For the vector →u of magnitude 20 and direction 0∘ to the horizontal axis, the vector is →u=^i20.
For the vector →v
of magnitude 40 and direction 60∘ to the horizontal axis, the vector is →v=^i40cos60∘+^j40sin60∘.
The resultant vector →w is the vector sum of the vectors, i.e.
→w=→u+→v
=^i20+^i40cos60∘+^j40sin60∘
=^i(20+40cos60∘)+^j(40sin60∘)
=^i40+^j20√3
For a vector ^ix+^jy, the magnitude of the vector is √x2+y2 and the direction above the horizontal axis is θ=tan−1(yx).
Let's use the formulas:
|→w|∠θ=√(40)2+(20√3)2∠tan−1(20√340)≈52.9∠40.9∘
The magnitude of the vector is about 53 units in the direction 41-degrees above the horizontal axis.
The magnitude of the resultant vector would be 60 units, and its direction will be 0°.
To find the magnitude and direction of the resultant vector when adding vectors u and v, we can use vector addition formulas:
Magnitude of the Resultant Vector (R):
R = √(u^2 + v^2 + 2uv * cosθ)
where:
u = magnitude of vector u (20)
v = magnitude of vector v (40)
θ = angle between vectors u and v (60°)
Plugging in the values:
R = √(20^2 + 40^2 + 2 * 20 * 40 * cos(60°))
≈ √(400 + 1600 + 1600)
≈ √3600
= 60
Direction of the Resultant Vector (θR):
Use the Law of Cosines to find the angle θR between the resultant vector R and vector u:
cosθR = (v^2 + R^2 - u^2) / (2 * v * R)
Plugging in the values:
cosθR = (40^2 + 60^2 - 20^2) / (2 * 40 * 60)
= (1600 + 3600 - 400) / 4800
= 1
Since cos(0°) = 1, we have θR = 0°.
So, the magnitude of the resultant vector is 60 units, and its direction is 0°.
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Please if someone knows the answer please help
what is the standard measurement system used by scientists around the world?
Answer:
Hey mate....
Explanation:
This is ur answer....
The International System of Units (SI), commonly known as the metric system, is the international standard for measurement.Hope it helps!
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International system of units.French système international d'Unitès, international decimal system of weights and measures derived from and extending the metric system of units.Adopted by the 11th General conference on weights and measures (CGPM) in 1960, It is abbreviated SI in all languages.
Explain this phase diagram by relating what you know about temperature, states of matter and
pressure.
Answer:
See explanation
Explanation:
The vertical axis corresponds to the pressure of a substance, while the horizontal axis corresponds to the temperature. The solid is the substance which contains particles of strong intermolecular force and compaction, typically ionic at a certain temperature, the liquid is the substance which contains relatively compact molecules, however lacks a particular arrangement. The gaseous substance is caused by particles with weak intermolecular forces, causing particle movement and collision with no arrangement whatsoever. The triple point as shown in the diagram, is the phrase on a diagram where each substance: solid, liquid and gas coexist. The critical point is the phase at which the/a substance is indistinguishable between liquid and gaseous states. A substance or elements state is highly dependent on its environment and it’s temperature, of which ultimately affects its kinetic energy within its particles. This is what the graph portrays and represents.
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John McRighteous has a mass of 90kg. Calculate johns weight.
Answer: W=M*gravity. 90 * 9.8=882N. That is the weight on Earth.
Explanation:
Calculating the weight is W=M*gravity. 90 * 9.8=882N. That is the weight on Earth.
Answer:
198.4 lbs
Explanation:
The graph below represents the relationship between velocity and time of travel for a toy car moving in a straight line.the shaded area under the line represents the toy cars
Answer:
Displacement
Explanation:
The definition of speed and the graphical analysis allows to find the result for the question of the meaning of the area under the curve is:
The area corresponds to the displacement of the body.
Velocity is defined as the variation of position with respect to time.
[tex]v = \frac{dx}{dt}[/tex]
Where v is the velocity, x the displacement and t the time.
If we make a graph of speed versus time, see attached, where we have a diagram of the process.
The expression of the velocity for the case of zero acceleration is
[tex]v = \frac{\Delta x}{\Delta t }[/tex]
Δx = v Δt
They indicate that the shaded section is under the curve, therefore it is
Area = Δv Δt
When comparing the two expressions they are equivalent, therefore the area is equal to the distance traveled.
In conclusion, using the definition of velocity and graphical analysis we can find the result for the question of the meaning of the area under the curve is:
The area corresponds to the displacement of the body.
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a 6.00-kg ornament is held at rest by two light wires that form 30° angles with the vertical, as shown in the figure. an external force of magnitude f acts vertically downward on the ornament. the tension exerted by each of the two wires is denoted by t. a free-body diagram, showing the four forces that act on the box, is shown in the figure. if the magnitude of force f is 410 n, what is the magnitude of the tension t?
The equilibrium condition allows finding the result for the tension of the cable that supports the block is:
The tension is: T₁ = 270.66 N
Newton's second law gives a relationship between force, mass and the acceleration of bodies, when the acceleration is zero it is called the equilibrium condition.
A free-body diagram of the forces is shown in the attachment.
Let's write the equilibrium equation for the vertical axis.
2 [tex]T_1_y[/tex] - f - W = 0
2 [tex]T_1_y[/tex] = W + f
Let's use trigonometry to find the tension, as the angle indicates that it is relative to the vertical.
cos 30 = [tex]\frac{T_1_y}{T_1}[/tex]
[tex]T_1_y[/tex] = T1 cos 30
We substitute.
2T₁ cos 30 = W + f
T₁ = m g + f / 2 cos 30
T₁ = [tex]\frac{6 \ 9.8 + 410}{2 \ cos 30}[/tex]
T₁ = 270.66 N
In conclusion using the equilibrium condition we can find the result for the tension of the cable that supports en bloc is:
The tension is: 270.66 N
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What are tadpoles? How does it look like
Answer: a tadpole is the first or second step into the evolution for a frog
Explanation: a frog starts with the egg then it becomes a tadpole for 6 to 12 weeks before it can start going out the water.
Answer:
Tadpoles are baby frogs. The tadpole looks like a frog with a tail and becomes a froglet around 12 weeks after hatching. The tadpole becomes an adult frog around 13 to 16 weeks after hatching.
Explanation:
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if v= 4.3 + 1.2% and I = 2.1A + 4.5% find the resistance and significant figures
If a FRAMESHIFT mutation causes a stop codon to be inserted into the DNA sequence
Answer:
The frameshift mutation will also alter the first stop codon ("UAA", "UGA" or "UAG") encountered in the sequence. The polypeptide being created could be abnormally short or abnormally long, and will most likely not be functional.
Explanation:
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What is the velocity at 10 seconds? PLEASE HELP!!!!!
Answer:
you you don't resource easy answer with great your your food look your photo this must be your photo near me pure cal is your office that is meaning of 5 to 10 2 5 10 20 1234 I don't know that time what to Theri 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 and 30 look this that this is wanting if you understand I look this victory 522436 the answer it 12 thankyou
A box collides with a ball as shown in the diagram below. After the collision, what
will the final momentum of the ball be?
BEFORE COLLISION
AFTER COLLISION
15 kgm/s
3 kgm/s
5 kgm/s
_kgm/s
O 18 kg * m/s
O 5 kg * m/s
O 10 kg * m/s
O 13 kg * m/s
The final momentum of the ball after collision is 13 kg.m/s.
The given parameters;
initial momentum of the box, P₁ = 15 kg.m/sinitial momentum of the ball, P₂ = 3 kg.m/sfinal momentum of the ball, P₃ = 5 kg.m/sLet the final momentum of the ball after collision = P₄
Apply the principle of conservation of linear momentum to determine the final momentum of the ball after collision;
total momentum before collision = total momentum after collision
P₁ + P₂ = P₃ + P₄
15 + 3 = 5 + P₄
18 = 5 + P₄
18 - 5 = P₄
13 = P₄
Thus, the final momentum of the ball after collision is 13 kg.m/s.
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write answers with significant figures:
a) 17.35 g +8.498 g
Answer:
25.9 g
Explanation:
= 17.35
8.498
________+
= 25.848 g = 25.85 g = 25.9 g
*so sorry if wrong
__________ is an example of a directional research hypothesis.
Answer:
Directional hypothesis is an example of a directional research hypothesis.
Explanation:
Directional hypothesis: A directional (or one tailed hypothesis) states which way you think the results are going to go, for example in an experimental study we might say…”Participants who have been deprived of sleep for 24 hours will have more cold symptoms in the following week after exposure to a virus than
whose geocentric model of the solar system was accepted for 1400 years
Answer:
Plato, Aristotle developed it further and used for 1400 years till Copernicus.
Explanation:
1. Give three examples, from the lab, where potential energy was converted to kinetic energy:
Answer:
A book on a table before it falls.
A yoyo before it is released.
A raised weight.
Explanation:
These are all examples of potential energy. So I hope you can find something that is comparable from the lab.
i need help with the second question
Answer:
c i think
Explanation:
Which statement is true about vectors?
Vectors need direction and magnitude to exist, otherwise, it becomes scalars that do not require direction to be expressed.
eg - Velocity is a vector as it needs direction, but speed is scalar and does not need direction
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Answer:
a. All quantities in physics are not vectors. b. A vector may have either magnitude or direction. c. The vector's length should be proportional to its magnitude. d. Two vectors can be added only if they have the same direction.
What is Obama's last name? PLZ PLZ PLZ THIS IS 500% OF MY GRADE PLS HELP PLS
Answer:
Barack Hussein Obama II
Explanation:
I think
Why do larger stars life a shortter life?
Answer:
A star's life expectancy depends on its mass. Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. ... A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years.