A system of 4 electrons, 18 protons, and 4 neutrons has a net charge of?
Answer:
+ 14
Explanation:
18 protons make a positive 18 charge (+18)
4 electrons make a negative 4 charge (-4)
both combined give + 18 - 4 = + 14
The four neutrons don't carry net charge, so the addition of the electrons doesn' affect the net charge found above which still gives + 14.
You wish to design a pendulum which moves a mass along an arc of length 40 cm when the angle with the vertical changes by 20 degrees. What should be the length L in meters of the pendulum? Enter the numerical answer without units. Your answer must be within 5% of the exact answer to receive credit.
Answer:
The length of the pendulum cord is approximately 114.592 centimeters.
Explanation:
We include a representation of the motion of the pendulum in the image attached below. The trajectory described by the pendulum is represented by the following geometrical expression:
[tex]s = \theta \cdot r[/tex] (1)
Where:
[tex]\theta[/tex] - Angular change with the vertical, measured in radians.
[tex]r[/tex] - Length of the pendulum cord, measured in centimeters.
[tex]s[/tex] - Arc, measured in centimeters.
If we know that [tex]\theta = \frac{\pi}{9}[/tex] and [tex]s = 40\,cm[/tex], then the length of the pendulum cord is.
[tex]r = \frac{s}{\theta}[/tex]
[tex]r = \frac{40\,cm}{\frac{\pi}{9} }[/tex]
[tex]r \approx 114.592\,cm[/tex]
The length of the pendulum cord is approximately 114.592 centimeters.
June does an experiment to study how salt affects the freezing point of water
Answer:
Salt melts ice and helps keep water from re-freezing by lowering the freezing point of water. This phenomenon is called freezing point depression. Salt only helps if there is a little bit of liquid water available. The salt has to dissolve into its ions in order to work.
Explanation:
A falling ball has potential energy of 5 J and a kinetic energy of 10 J. What is the ball's mechanical energy?
Which of the following describes the motion or change caused by a transformation from electrical to sound energy? (2 points) a A child listens to the music from a trumpet. b A dog howls to the siren from a police car. c A person moves their arm when they hear the buzz of a fly. d Music comes out from a television speaker.
Answer:
d.music comes out from a television speaker
Explanation:
because television use electricity (electrical energy) and produce sound (sound energy) that we hear while watching tv
Answer:
The answer would be (D) Music comes out from a television speaker.
Explanation:
This is because the TV uses electrical energy from where its plugged in. And the speaker is the sound energy which is caused by the TV to go with the show you are watching.
Hope this helps!
Lifting a stone block 146m to the top of the Great Pyramid required 146,000 J of work. How much work was done to lift the block halfway to the top?
A. 36,500 Joules
B. 73,000 Joules
C. 146,000 Joules
D. 292,000 Joules
Please help me.
A net force F acts on a mass m and produces an acceleration a. What acceleration results if a net force 4F acts on a mass 6m?
Answer: The acceleration results if a net force of 4F acts on a mass of 6m is 2/3a.
Explanation:
Force exerted on an object can be defined as a pull or a push on an object which leads to it's displacement. Force is taken to be a vector quantity because it has both magnitude and direction. The formula which can be used to determine force exerted on an object in physics is:
F= mass( kg) × acceleration( m/ s²)
Acceleration is defined as the rate at which the velocity of an object changes. From the formula of force given above it can be determined by making it the subject of formula. Therefore acceleration= Force/ mass.
From the question,
Force= 4F
Mass= 6m
Therefore acceleration= F/m
= 4/6
Acceleration= 2/3a
The required magnitude of acceleration when force is 4F and mass is 6m is 2/3a.
Given data:
The magnitude of net force is, 4F.
The value of mass is, 6m.
Apply the Newton's second law which says that force exerted on an object can be defined as a pull or a push on an object which leads to it's displacement. Force is taken to be a vector quantity because it has both magnitude and direction. The formula which can be used to determine force exerted on an object in physics is
F = ma
a = F/m ..........................................(1)
here, a is the acceleration.
Solving as when the force becomes 4F and mass becomes 6m.
[tex](4F) = (6m) \times a'\\\\a '= \dfrac{4F}{6m}\\\\a '= \dfrac{2}{3}a[/tex]
Thus, the required magnitude of acceleration when force is 4F and mass is 6m is 2/3a.
Learn more about the Newton's Second law here:
https://brainly.com/question/13447525
Suppose the flow rate of blood in a coronary artery has been reduced to half its normal value by plaque deposits. By what factor has the radius of the artery been reduced, assuming no turbulence occurs?
Strategy
Assuming laminar flow, Poiseuilleâs law states that
Q = (p2 - p1)pir^4/8nl.We need to compare the artery radius before and after the flow rate reduction.
Answer:
1.18
Explanation:
The flow rate of blood is proportional to the fourth power of its radius as given the Poiseuille's law.
The law is :
[tex]$Q \propto r^4$[/tex]
It is given here that the flood flow rate is been reduced to half its normal value. Therefore, [tex]$Q_1 = \frac{1}{2}Q_2$[/tex]
So, for the radius [tex]$r_1$[/tex] and [tex]$r_2$[/tex], the ratios of their flow rates are :
[tex]$\frac{Q_1}{Q_2}=\frac{r_1^4}{r_2^4}$[/tex]
It is given that the flow rate is reduced to half. So we have,
[tex]$\frac{Q_1}{2Q_1}=\frac{r_1^4}{r_2^4}$[/tex]
or [tex]$r_2=2^{1/4}{r_1}$[/tex]
[tex]$r_2=1.18 \ r_1}$[/tex]
So the radius changes by a factor of 1.18
A sample contains 20 kg of radioactive material. The decay constant of the material is 0.179 per second. If the amount of time that has passed is 300 seconds, how much of the of the original material is still radioactive? Show all work
Answer:
6,000 kg
Explanation:
1. When asteroids collided some of the broken materials fall into Earth's orbit. What do
astronomers call the debris when it hits planet Earth?
Answer:
meteoroids
Explanation:
when an asteroid (or really anything else) falls to earth, it is called a meteoroid
A golf ball hit off a tee on level ground, lands 62 m away 3.0 later. What was the initial velocity of the golf ball?
62×3.0
think so not sure
The amount of time for a synchronous input to a flip-flop to be stable before the rising edge of clock is called the hold time. a) True b) False
Answer:
true
Explanation:
Answer:
true
Explanation:
The volume of water in a measuring cyclinder is 50 ml .When a piece of stone is immeresed in the cyclinder the volume of water increases to 87.3ml. Calculate volume of stone.
Answer:
37.3ml
Explanation:
87.3 ml-50 ml=37.3ml
Answer:
ok
Explanation:
g
Describe and give an example of mutualism.
Describe and give an example of commensalism.
Describe and give an example of parasitism.
Describe and give an example of competition.
Describe and give an example of predation.
Answer:
Mutualism, commensalism, parasitism, competition, and predation.
Explanation:
mutualism- relationship between two or more organisms where both are benefited. Example-oxpecker with rhino/zebra. They eat bugs off of them which means that they are getting food, while the rhino/zebra are getting cleaned up with pest control.
commensalism- relationship between two organisms where one benefits and the other isn't benefited or harmed. EX- tree frogs use plants as protectioin.he frog is benefited, and the plant is neither harmed nor benefited. Remora fish have a disk on their heads that they use to attach themselves to larger animals for protection. The animals they attach to are neither harmed nor benefited.
parasitism- in a relationship where an organism benefits at the expense of the other. (one is benefited while the other is harmed) ex- fleas and ticks that live on cats and dogs, tape worms that live in people and animals that eat the food which means that the people aren't getting the food or nutrition that they eat. lice, etc
competition- interaction within organisms/species in which both the organisms/species are harmed and is apart of natural selection. Examples may include two males fighting over a mate, animals competing over food, limited habitats that they are fighting over, territory, etc.
predation- the preying of one animal on another. It's where the predator hunts and eats another organism which is its prey. categorized within-(1) carnivory, (2) herbivory, (3) parasitism, and (4) mutualism. Each type of predation can by categorized based on whether or not it results in the death of the prey.ex- owls hunting mice, wolves hunting rabbits, lion hunting gazelle, etc.
When does a magnet induce an electric current in a wire coil?
O A. When the wire is connected to the coil
O B. When the magnet is near the coil
O C. When the magnet is moving back and forth in the coil
D. When the magnet is very strong
Answer:
B I believe
Explanation:
A plane moves at a speed of 100 mi/h and takes flight on a 25 degree angle. What is the VERTICAL speed in mi/h? Round to the nearest whole number and DO NOT include units (Ex: 11).
Answer:
The vertical speed in mi/h is 42.
Explanation:
Rectangular Components of a Vector
A 2D vector can be expressed in several forms. The rectangular form gives its two components, one for each axis (x,y). The polar form gives the components as (r,θ) being r the magnitude and θ the angle.
The relationships between the coordinates of both systems are shown in the image below.
When the magnitude and angle of the vector are given, the rectangular components are calculated as follows:
[tex]v_x=v\cos\theta[/tex]
[tex]v_y=v\sin\theta[/tex]
Where v is the magnitude of the vector and θ is the angle with respect to the x positive direction.
We are given the magnitude of the velocity (the speed) at which a plane is moving as v=100 mi/h at an angle of θ=25°, the vertical component of the velocity is:
[tex]v_y=100\sin 25^\circ[/tex]
Calculating:
[tex]v_y=42.26\approx 42[/tex]
The vertical speed in mi/h is 42.
2. An ambulance traveling at 20 m/s emits a sound at 500 Hz. What frequency does a person standing on the corner of a street detect?
there’s a tornado warning where i live rn
Answer:
same
Explanation:
aww good luck, i hope u n ur family turn out okkk
what are the laws of newton
Answer:
Explanation:
These are the laws of Newton
Answer:
the first law, an object will not change its motion unless a force acts upon it. the 2nd one, the force of an object is equal to its mass times it acceleration. the 3rd one is when 2 objects interact, they apply forces to each other of equal magnitude and opposite direction.
Just some Naruto couples having a Boxing Match.
Who do you think will win?! Naruto and Hinata or Pain and Konan?!
Answer:
naruto and hinata
Explanation:
What unbalanced force is needed to give a 976 kg vehicle an acceleration of 2.50 m/s2? ASAP
Answer:
2440 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 976 × 2.5
We have the final answer as
2440 NHope this helps you
A rod is pivoted about its center and oriented horizontally. A 5.0-N force directed upward is applied 4.0 m to the left of the pivot and another upward 5.0-N force is applied 1.5 m to the right of the pivot. What is magnitude of the total torque about the pivot?
Answer:
The total torque is 27.5 Nm
Explanation:
Given;
5.0-N force directed upward is applied 4.0 m to the left of the pivot,
5.0-N force directed upward is applied 1.5 m to the right of the pivot,
Taking the moment about the pivot, the total torque is given by;
τ = Fr
where;
F is the appllied force
r is the radius of the force arm
τ = (5 N x 4 m) + (5 N x 1.5 m)
τ = 27.5 Nm
Therefore, the total torque is 27.5 Nm
What is the approximate horizontal velocity at which the boy in the diagram
threw the ball?
a. +5m/s
b. +20m/s
c. +25m/s
d. +30m/s
Answer:
D
Explanation:
5+25=30
Use the drop-down menus to complete each sentence.
A plant grows toward a sunny window. This response is an example of
✔ phototropism
.
Sometimes a plant grows around a tree for support. This response is an example of
✔ thigmotropism
.
The roots of a plant grow toward a water source. This response is an example of
✔ hydrotropism
.
The roots of a plant grow down into the soil. This response is an example of
✔ gravitropism
.
the answers are already there
Answer:
The correct answer is - phototropism, thigmotropism, hydrotropism, and gravitropism in order ( already match correctly).
Explanation:
phototropism is a phenomenon in which plants grow towards the light or sun which is accomplished by the hormone auxin in the cells far from the light.
Thigotropism is a type of plant growth that occurs around the tree to support itself which is a touch stimuli response.
The movement of the plant in the direction of the source of the water is known as hydrotropism. In which stimuli is humidity or the water concentration.
The movement of the plant or roots of the plants towards the soil or earth is known as gravitropism here gravity is the stimuli.
Answer:
Use the drop-down menus to complete each sentence.
A plant grows toward a sunny window. This response is an example of
phototropism
.
Sometimes a plant grows around a tree for support. This response is an example of
thigmotropism
.
The roots of a plant grow toward a water source. This response is an example of
hydrotropism
.
The roots of a plant grow down into the soil. This response is an example of
gravitropism
.
Explanation:
A film of soapy water on top of a plastic cutting board has a thickness of 255 nm. What wavelength and color is most strongly reflected if it is illuminated perpendicular to its surface?
Answer:
the reflected wavelength is lano = 4.55 10⁻⁷ m which corresponds to the blue color
Explanation:
This is a case of reflection interference, we must be careful
* There is a 180º phase change when light passes from the air to the soap film (n = 1,339), but there is no phase change when passing from the pomp to the plastic (n = 1.3)
* the wavelength within the film is modulated by the refractive index
λₙ = λ₀ / n
if we consider these relationships the condition for constructive interference is
2 t = (m + ½) λₙ
2t = (m + ½) λ₀ / n
λ₀ = 2t n / (m + ½)
we substitute the values
λ₀= 2 255 10⁻⁹ 1,339 / (m + ½)
λ₀ = 6.829 10⁻⁷ (m + ½)
let's calculate the wavelength for various interference orders
m = 0
λ₀ = 6.829 10⁻⁷/ ( 0 + ½ )
λ₀ = 13.6 10⁻⁷
it is not visible
m = 1
λ₀ = 6,829 10⁻⁷/ (1 + ½)
λ₀ = 4.55 10⁻⁷
color blue
m = 2
λ₀ = 6.829 10⁻⁷ / (2 + ½)
λ₀ = 2,7 10⁻⁷
it is not visible
therefore the reflected wavelength is lano = 4.55 10⁻⁷ m which corresponds to the blue color
A magnet of mass 0.20 kg is dropped from rest and falls vertically through a 35.0 cm copper tube. Eddy currents are induced, causing the copper to warm up. The speed of the magnet as it emerges from the tube is 1.50 m/s. How much heat energy is dissipated to the environment?
Answer:
The energy lost to the environment is 0.461 J
Explanation:
Given;
mass of the magnet, m = 0.2 kg
height of fall, h = 35 cm = 0.35 m
initial speed of the magnet, u = 0
final speed of the magnet, v = 1.5 m/s
Initial energy of the magnet is given by;
E₁ = P.E₁ + K.E₁
E₁ = mgh₁ + ¹/₂mu²
E₁ = (0.2 x 9.8 x 0.35) + ¹/₂(0.2)(0)²
E₁ = 0.686 J
Final energy of the magnet as it emerges from the tube is given by;
E₂ = mgh₂ + ¹/₂mv²
E₂ = (0.2 x 9.8 x 0) + ¹/₂(0.2)(1.5)²
E₂ = 0 + 0.225 J
The energy lost to the environment is given by;
E = E₂ - E₁
E = 0.225 J - 0.686 J
E = -0.461 J (negative sign indicates lost energy to the environment)
Therefore, the energy lost to the environment is 0.461 J
What statement is TRUE about all the substances listed in the data table? A) All the substances conduct electricity. B) All the substances are strong electrolytes. All the substances have high dissociation constants. D) All the substances contain an equal amount of ions in solution. Eliminate
Answer:
A) all substance conduct electricity
As a rough model of the impact of walking/running, consider that half the mass of the body falls from a height of 4.77-cm onto a single foot. (During a typical stride, an adult's center-of-mass moves approximately this distance vertically). Use the kinematic equations to calculate the speed of an object falling from this height at the moment of impact with the ground under the influence of gravity.A. As a rough model of the impact of walking, consider that half of the mass of the entire body strikes the ground with a downward velocity of 1.0 m/s and comes to a full vertical stop over an impact duration of 20 ms. Calculate the force associated with this single step for a person with a mass of 74.2 kg. B. Calculate the stress (solid pressure) of a force of 1880 N applied across the 0.4 cm^2 cross-sectional area of the typical Achilles tendon. For reference, the maximum rupture stress of tendons has been reported in the range of 100-150 MPa.
Answer:
0.967 m/s
1855 N
[tex]46.375\ \text{MPa}[/tex]
Explanation:
v = Final velocity
u = Initial velocity = 0
s = Displacement = 4.77 cm
g = a = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
From the kinematic equations
[tex]v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times 9.81\times 0.0477+0}\\\Rightarrow v=0.967\ \text{m/s}[/tex]
The velocity of the object at the moment of impact is 0.967 m/s
Now
[tex]\Delta v[/tex] = Change in velocity = 1 m/s
t = Time taken = 20 ms
m = Half mass of the person = [tex]\dfrac{74.2}{2}=37.1\ \text{kg}[/tex]
[tex]F=\dfrac{m}{t}\\\Rightarrow F=\dfrac{37.1\times 1}{20\times 10^{-3}}\\\Rightarrow F=1855\ \text{N}[/tex]
The force associated with a single step of the person is 1855 N
A = Area = [tex]0.4\ \text{cm}^2[/tex]
Stress is given by
[tex]\sigma=\dfrac{F}{A}\\\Rightarrow \sigma=\dfrac{1855}{0.4\times 10^{-4}}\\\Rightarrow \sigma=46375000\ \text{Pa}=46.375\ \text{MPa}[/tex]
The stress on the tendon is [tex]46.375\ \text{MPa}[/tex]
The speed of object during falling is 0.967 m/s.
(A) The magnitude of force associated with this single step for a person is 1855 N.
(B) The required value of stress at tendons is [tex]4.70 \times 10^{7} \;\rm Pa[/tex].
Given data:
The height of fall is, h = 4.77 cm = 0.0477 m.
The magnitude of downward velocity is, v' = 1.0 m/s.
The duration of impact is, [tex]t = 20 \;\rm ms =20 \times 10^{-3} \;\rm s[/tex].
The mass of person is, m = 74.2 kg.
The magnitude of force is, F' = 1880 N.
The cross-sectional area is, [tex]A =0.4 \;\rm cm^{2} = 0.4 \times 10^{-4} \;\rm m^{2][/tex].
The problem has several parts using different concepts. First obtain the final speed of object to fall by using the second kinematic equations of motion as,
[tex]v^{2}=u^{2}+2gh[/tex]
Solving as,
[tex]v^{2}=0^{2}+(2 \times 9.8 \times 0.0477)\\\\v = \sqrt{(2 \times 9.8 \times 0.0477)} \\v = 0.967 \;\rm m/s[/tex]
Thus, the speed of object during falling is 0.967 m/s.
(A)
Now coming to next part, the half of mass means, m' = m/2 = 74.2/2 = 37.1 kg.
Apply the expression of average force as,
[tex]F =\dfrac{m'v'}{t}[/tex]
Solving as,
[tex]F =\dfrac{37.1 \times 1}{20 \times 10^{-3}}\\\\F = 1855 \;\rm N[/tex]
Thus, the magnitude of force associated with this single step for a person is 1855 N.
(B)
The expression for the stress is given as,
[tex]\sigma = \dfrac{F'}{A}[/tex]
Solving as,
[tex]\sigma = \dfrac{1880}{0.4 \times 10^{-4}}\\\\\sigma =4.70 \times 10^{7} \;\rm Pa[/tex]
Thus, the required value of stress at tendons is [tex]4.70 \times 10^{7} \;\rm Pa[/tex].
Learn more about the Stress force here:
https://brainly.com/question/18274389
what do we call the games that involve different manipulation skills like throwing,tossing,rolling,catching,running,jumping,hopping and stretching what is the answer A.puzzle game B.simulation games C.target games D.role-playing games
Jolie is on the weightlifting team at her school. She must lift as much weight as possible from the ground to a standing straight position. How much work will Jolie do if she uses a force of 5N to lift 150 pounds to a height of 1.5m? 0 2.3) O 6.5) 7.5) 0 3.3)
Answer:
=7.5J
Explanation:
Step one:
given data
the applied force F=5N
the distance = 1.5m
Step two:
Required
work done by Jolie
Now by definition, the work done is the applied times the distance which the force is applied
Wd= F*D
Wd= 5*1.5
Wd=7.5J
If she uses a force of 5N to lift 150 pounds to a height of 1.5m, the work done will be 7.5J