Answer:
B, caused by the presence of mass
Explanation:
A 5 kg block is pulled along a horizontal surface by a 28N force to the right. Compute
the acceleration of the block if the surface is
a)
smooth,
b)
rough with a coefficient of kinetic friction of 0.23 between the block and the
surface.
[ 5.6ms 2,3.4ms]
(a) Without friction, Newton's second law tells us the net horizontal force is such that
28 N = (5 kg) a
a = (28 N) / (5 kg)
a = 5.6 m/s²
(b) With friction (magnitude f ), we get a net horizontal force such that
28 N - f = (5 kg) a
and a net vertical force such that
n - w = 0
since the block is only being pulled horizontally, where w is the weight of the block and n is the magnitude of the normal force. So
n = w = (5 kg) (9.8 m/s²)
n = 49 N
Friction is proportional to the normal force such that
f = µ n
We're given µ = 0.23, so
f = 0.23 (49 N)
f ≈ 11 N
Solve for a :
28 N - 11 N = (5 kg) a
a = (17 N) / (5 kg)
a = 3.4 m/s²
An electron (m = 9.1 × 10−31 kg, q = −1.6 × 10−19 C) starts from rest at point A and has a speed of 5.0 × 106 m/s at point B. Only electric forces act on it during this motion. Determine the electric potential difference VA − VB.a) −71 Vb) +71 Vc) −26 Vd) +26 Ve) −140 V
Answer:
-71 V
Explanation:
Given that,
An electron starts from rest at point A and has a speed of 5.0 × 10⁶ m/s at point B.
We need to find the electric potential difference [tex]V_A-V_B[/tex]. It can be calculated by using the conservation of charges as follows :
[tex]qV=\dfrac{1}{2}mv^2[/tex]
m and q are mass and charge on electrons
[tex]V=\dfrac{mv^2}{2(-q)}\\\\V=-\dfrac{9.1\times 10^{-31}\times (5\times 10^6)^2}{2\times 1.6\times 10^{-19}}\\\\V=-71.09\ V[/tex]
So, the electric potential difference is (-71 V). So, the correct option is (a).
If the marshmallows represent the atoms in the substance, which change of state is Freida modeling Freida wants to model the way atoms move when a substance changes its state. To do this, Freida makes a pyramid of marshmallows. Then, she knocked down the pyramid causing the marshmallows to fall. O melting O freezing O condensation O deposition
Answer: Melting
Explanation:
When Frieda made a pyramid of marshmallows, she was representing the atoms in a solid substance as the atoms are clumped together and unable to move.
When she then knocks it down, she is showing the movement of atoms in a liquid substance as they are now freer than they were before. The process by which substances go from solid to liquid is melting.
Answer: Melting
Explanation: When Frieda made a pyramid of marshmallows, she was representing the atoms in a solid substance as the atoms are clumped together and unable to move.
When she then knocks it down, she is showing the movement of atoms in a liquid substance as they are now freer than they were before. The process by which substances go from solid to liquid is melting.
The fire department arrive to a fire in 210 seconds after leaving the fire station to the burning building which is 840m away. How fast did they travel?
Answer: The speed is 4 meters per second or 4 m/s.
Explanation:
First, we have the relationship:
Speed = Distance/Time.
In this case, we know that the fire department arrives to a fire in 210 seconds after leaving the fire station to the burning building which is 840m away, this means that:
Time = 210 seconds
Distance traveled in that time = 840m.
Then the speed is:
Speed = 840m/210s = 4 m/s.
The speed is 4 meters per second.
Since the triangle below contains an obtuse angle what type of angle must angle x be
Answer:
greater than 90 degrees
Explanation:
I need help lol .........
Answer:
a
Explanation:
A bicycle travels at a velocity of 2.33 m/s, and has a displacement of -58.3 m. How much time did it take?
Answer:
The time will be: 25.02 seconds
Explanation:
Given
A bicycle travels at a velocity of 2.33 m/s.
i.e.
v = 2.33 m/sand
displacement = d = 58.3 mAs we know the formula to find the time
Time = Displacement/Velocity
= d/v
= 58.3/2.33
= 25.02 seconds
Therefore, the time will be: 25.02 seconds
Which best describes her speed and velocity? (There are 60 seconds in 1 minute.) Her speed is 4.4 m/s, and her velocity is 0 m/s. Her speed is 1.1 m/s, and her velocity is 0 m/s. Her speed is 0 m/s, and her velocity is 2400 m/s. Her speed is 4.4 m/s, and her velocity is 4.4 m/s.
Answer:
A
Explanation:
Yw :)
Answer:
a
Explanation:
This story makes use of personification as one of the main figures of speech.
7. 100 Joules of work was done to move an object with a force of 15 N. How far did the
object move?
Answer:Distance=6.67 (rounded)
Explanation: Work = Force x Distance.
100 Joules of work= force of 15 N x Distance (?)
The work equation given above can be rearranged to find force or distance if the other variables are known:
Distance=Work / force
Distance=100Joules/15 N
Distance=6.67 (rounded)
By quadrupling the mass of the body hanging on the thread what will become the period of oscillation?
Well, the tension in the thread will probably quadruple, but the hanging body will continue to just hang there.
The question gives us no evidence that it is doing any oscillating, and there's no reason for it to start just because it suddenly got heavier.
What happens during free association? A person talks about a dream, making connections by openly talking. A therapist helps you learn empathy for others. You explore the role of the brain's functions in the dream. You discuss your feelings and analyze your emotions.
Answer:
You discuss your feelings and analyze your emotions.
Explanation:
During free association a therapist or psychoanalyst helps you discuss your feelings and analyze your emotions.
Free association allows patients to discuss their minds freely without any censorship. This helps people to communicate freely without placing any barrier on their free thought pattern. All the thoughts that comes to mind are encouraged to be expressed and spoken.Answer:
In traditional free association, a person in therapy is encouraged to verbalize or write all thoughts that come to mind. Free association is not a linear thought pattern. Rather, a person might produce an incoherent stream of words, such as dog, red, mother, and scoot. They may also jump randomly from one memory or emotion to another.
THE ANSWER IS B
PLEASE MARK BRANIEST
A child of mass m is released from rest at the top of a water slide,
at height h=8.8 m above the bottom of the slide. Assuming that the slide
is frictionless because of the water on it, find the child’s speed at the bottom of the slide
Answer:
From the concept of energy conservation, Ei=Ef
Explanation:
mgh=1/2mv^2
=> v=
\sqrt{2gh}2gh
=
\sqrt{2 \times 9.8 \times 8.8}2×9.8×8.8
=
\sqrt{172.28}172.28
=13.12m/s.
Which statements describe the types of energy emitted by the Sun? Check all that apply.
It emits most of its energy in gamma rays.
It emits all wavelengths in the electromagnetic spectrum.
It emits most of its energy as visible light.
Its peak wavelength is in the orange-yellow range.
It emits no X-rays or radio waves.
Its peak wavelength is in the yellow-green range.
The statement that describes the types of energy emitted by the Sun is that It emits all wavelengths in the electromagnetic spectrum, therefore the correct answer is option B.
What is electromagnetic radiation?Electromagnetic radiation is a type of energy radiation produced by the propagation of electromagnetic waves that are produced for natural as well as anthropogenic reasons.
As given in the problem we have to find out which statements describe the types of energy emitted by the Sun from the given list of options,
Thus, Sun emits all wavelengths in the electromagnetic spectrum, which means that option B is the appropriate response.
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You are out and about in the country and your father sees a rock that he really wants in the yard. Now you must get the very heavy rock into the back of a truck. The truck bed is 3 feet off the ground. Your father pulls out a 5-foot plank and begins to set up a ramp. At the same time, you have found a plank that is 8 feet long, and you show it to your father.
1. Which plank will give you the most mechanical advantage?
Show your step by step work.
Answer:
The 8ft ramp
Explanation:
L/h
5/3
1.66
1.66:1
L/h
8/3
2.66
2.66:1
8ft is the ramp that would give you the most amount of mechanical advantage.
Explain why increasing the mass of a car affects how the car rolls down a ramp.
Answer:
Q1) Explain why increasing the mass of a car affects how the car rolls down a ramp
Ans1) Weight affects speed down the ramp but it's the mass that affects speed after a car leaves the ramp. Heavier cars have more momentum, so they travel further, given the same amount of friction
(a) A man stands a distance d = 0.325 m from the left end of a platform as shown in the figure. The platform is supported by three lines. Find the tension in each line (in N). Assume the platform is uniform, with length L = 2.00 m and mass 30.5 kg, and the weight of the man is 675 N. (Due to the nature of this problem, do not use rounded intermediate values in your calculations—including answers submitted in WebAssign.)
A small lead ball, attached to a 1.75-m rope, is being whirled in a circle that lies in the vertical plane. The ball is whirled at a constant rate of three revolutions per second and is released on the upward part of the circular motion when it is 2.1 m above the ground. The ball travels straight upward. In the absence of air resistance, to what maximum height above the ground does the ball rise?
Answer:
h = 57.6 m
Explanation:
First, we find the linear speed of the ball while in circular motion:
v = rω
where,
v = linear speed of ball = ?
r = radius of circle = length of rope = 1.75 m
ω = angular speed = (3 rev/s)(2π rad/1 rev) = 18.84 rad/s
Therefore,
v = (1.75 m)(18.84 rad/s)
v = 32.98 m/s
Now, we apply the 3rd equation of motion on the ball, when it breaks:
2gh = Vf² - Vi²
where,
g = - 9.8 m/s² (negative sign due to upward motion)
h = height covered = ?
Vf = Final Velocity = 0 m/s (since, the ball finally stops at highest point for a moment)
Vi = Initial Velocity = 32.98 m/s
Therefore,
2(- 9.8 m/s²)h = (0 m/s)² - (32.98 m/s)²
h = ( - 1088.12 m²/s²)/( - 19.6 m/s²)
h = 55.5 m
since, the ball was initially at a height of 2.1 m from ground. So, the total height from ground, will now become:
h = 55.5 m + 2.1 m
h = 57.6 m
A bird flies with a constant velocity of 100m/s for 10 minutes. calculate the magnitude of the displacement.
Answer:
s = ut
= 100 m/s * 10*60 s
= 60000m
= 60km
Answer:
60 km
Explanation:
velocity (v) = 100m/s
t = 10 minutes = 10(60) = 600 seconds
displacement = velocity × time
s = v × t
s = 100 × 600
s = 60,000m
s = 60,000/1000 km
s = 60km
Plz help I don’t know what to do
what process resurfaces Venus?
The catastrophic resurfacing model suggests that planetary resurfacing on Venus occurred through infrequent, planet-wide volcanic events, large enough to bury all earlier material. In other words, resurfacing was a near-instantaneous change to Venus relative to the slow flow of geologic time.
Answer:
Infrequent, planet-wide volcanic events resurface Venus.
Explanation:
Which statements about our solar system are false?
Our solar system is made up of the Sun and other objects that orbit the Sun.
The Sun is the only star in our solar system.
Dwarf planets have several other bodies in their path orbiting the Sun just as they do.
The Kuiper Belt is between Uranus and Neptune.
A large number of irregularly shaped comets are located in a vast ring between the orbits of Mars and Jupiter.
Answer:
c
and d
Explanation:
When light of frequency equal to 2.11 x 10^-15 s-1 shines on the surface of gold metal, the kinetic energy of ejected electrons is found to be 5.83 x 10^-19 J. What is the work function of gold?
Answer:
Work function, [tex]W=5.83\times 10^{-19}\ J[/tex]
Explanation:
Given that,
Frequency of light, [tex]f=2.11\times 10^{-15}\ Hz[/tex]
Kinetic energy of the ejected electrons, [tex]E_k=5.83\times 10^{-19}\ J[/tex]
We need to find the work function of the gold. Let it is W.
Using Einstein's photoelectric equation as follows :
[tex]W=hf-E_K\\\\W=6.63\times 10^{-34}\times 2.11\times 10^{-15}-5.83\times 10^{-19}\\\\W=-5.83\times 10^{-19}\ J[/tex]
So, the work function of gold is [tex]5.83\times 10^{-19}\ J[/tex].
When the displacement of a mass on a spring is 12 A, what percentage of the energy is kinetic energy? At what displacement, as a fraction of A, is the energy half kinetic and half potential?
Answer:
75%
[tex]\dfrac{A}{\sqrt{2}}[/tex]
Explanation:
x = Displacement of spring = [tex]\dfrac{1}{2}A=\dfrac{A}{2}[/tex]
k = Spring constant
Total energy of the spring is
[tex]E=\dfrac{1}{2}kA^2[/tex]
Elastic potential energy is given by
[tex]U=\dfrac{1}{2}kx^2\\\Rightarrow U=\dfrac{1}{2}k(\dfrac{A}{2})^2\\\Rightarrow U=\dfrac{1}{2}k\dfrac{A^2}{4}\\\Rightarrow U=\dfrac{1}{4}\times \dfrac{1}{2}kA^2\\\Rightarrow U=\dfrac{1}{4}E[/tex]
Total energy is given by
[tex]E=U+K\\\Rightarrow K=E-U\\\Rightarrow K=E-\dfrac{1}{4}E\\\Rightarrow K=\dfrac{3}{4}E\\\Rightarrow \dfrac{K}{E}=0.75[/tex]
The percentage will be
[tex]\dfrac{K}{E}=0.75\times 100\%\\\Rightarrow \dfrac{K}{E}=75\%[/tex]
The required percentage is 75%
According to the given condition
[tex]\dfrac{E}{2}=\dfrac{1}{2}kx^2\\\Rightarrow \dfrac{\dfrac{1}{2}kA^2}{2}=\dfrac{1}{2}kx^2\\\Rightarrow \dfrac{1}{2}kA^2=kx^2\\\Rightarrow x=\sqrt{\dfrac{1}{2}A^2}\\\Rightarrow x=\dfrac{A}{\sqrt{2}}[/tex]
So, the energy is half when displacement is [tex]\dfrac{A}{\sqrt{2}}[/tex]
Let x be the displacement of spring which is given to be [tex]\frac{1}{2} A=\frac{A}{2}[/tex]
k= spring constant
Total energy of the spring is:
[tex]E=\frac{1}{2} kA^2[/tex]
Elastic potential energy is given as:
[tex]U=\frac{1}{2} kx^2[/tex]
Now on substituting the value of x in above equation:
[tex]U=\frac{1}{2} k\frac{A^2}{4}[/tex]
It can also be written as:
[tex]U=\frac{1}{4} *\frac{1}{2} kA^2 \\\\U=\frac{1}{4} E[/tex] (∵[tex]E=\frac{1}{2} kA^2[/tex])
Total energy can be written as:
E=U+K
⇒K=E-U
⇒K=E-1/4 E
⇒K=3/4 E
⇒[tex]\frac{K}{E} =0.75[/tex]
(i) Now, we need to calculate the percentage of kinetic energy:
[tex]\frac{K}{E} =0.75*100=75\%[/tex]
The percentage of kinetic energy is 75%.
(ii) In second it is asked at what displacement, as a fraction of A, is the energy half kinetic and half potential?
∴[tex]\frac{E}{2} =\frac{1}{2} kx^2[/tex]
On substituting the value of E in above equation we will get:
[tex]x=\sqrt{\frac{1}{2} A^2} \\\\x=\frac{A}{\sqrt{2} }[/tex]
So, the energy is half when displacement is [tex]\frac{A}{\sqrt{2} }[/tex] .
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Two pickup trucks each have a mass of 2,000 kg. The gravitational force between the trucks is 3.00 × 10-5 N. One pickup truck is then loaded with 1,000 kg of bricks. Which of the following would be the new gravitational force between the two trucks?
Answer:
New gravitational force would be: [tex]4.5\,\,\,10^{-5}\,\,\,N[/tex]
Explanation:
Recall the general form of the gravitational force between two objects of masses m1 and m2 separated a distance "d":
[tex]F_g=G\,\frac{m1\,*\, m2}{d^2}[/tex]
which for the 2000 kg trucks becomes:
[tex]F_g=G\,\frac{m1\,*\, m2}{d^2} \\3\,\,\,10^{-5}\,N=G\,\frac{2000\,*\, 2000}{d^2}[/tex]
when we add 1000 kg of bricks to one truck, we get the following unknown force (x) that we need to find:
[tex]F_g=G\,\frac{m1\,*\, m2}{d^2} \\x=G\,\frac{3000\,*\, 2000}{d^2}[/tex]
Now we divide term by term the last equation by the previous one, in order to cancel out common factors to both equation (G, d^2) and get the following equation:
[tex]\frac{x}{3\,\,\,10^{-5}} =\frac{3000}{2000} \\x=\frac{9}{2} \,10^{-5} =4.5\,\,\,10^{-5}\,\,\,N[/tex]
Which best describes a metal such as Silver (Ag)?
Group of answer choices
Brittle, a good conductor, and ductile.
Lustrous, malleable, and forms cations.
Dull, highly reactive, and a semiconductor.
Low melting point, forms anions, good insulator.
Answer:
Brittle, a good conductor, and ductile.
According to the electronic configuration and position of silver in periodic table it can be inferred that it is brittle , good conductor and ductile.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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Which of the following elements is more reactive than the
Answer:
you need to attach a picture so I can answer it
A car staring from rest accelerates at 12 m/s^2, what distance did it travel in 7 seconds? (Show work)
Which refers to any disturbance that carries energy from one place to another through matter and space?
frequency
wave
hertz
pitch
Answer:
I think the answer is frequency
Answer:
wAvE
Explanation:
i have my ways
What is the frequency of a wave that has a wavelength of 2000 meters and is traveling at 20 m/s?
Answer:
freqiency=velocity/wavelength
ief=20/2000=0.01hz