Answer:
Vf = 18.78 m/s
Explanation:
As, the block does not trunk does not slide while falling. hence, we can use third equation of motion to find its velocity before it hits the ground:
2gh = Vf² - Vi²
where,
g = acceleration due to gravity = 9.8 m/s²
h = Height of Trunk = 18 m
Vf = Velocity of trunk just before it hits the ground = ?
Vi = Initial Velocity of the trunk = 0 m/s
Therefore, using these values in the equation, we get:
(2)(9.8 m/s²)(18 m) = Vf² - (0 m/s)²
Vf = √(352.8 m²/s²)
Vf = 18.78 m/s
How does an electric motor use magnetic force to produce motion?
The north pole of a permanent magnet placed in the center of an electromagnet attracts the north pole of the electromagnet.
The north pole of an electromagnet placed in the center of a permanent magnet attracts the north pole of the permanent magnet.
The north pole of a permanent magnet placed in the center of an electromagnet repels the north pole of the electromagnet.
The north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet.
Answer:
The north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet.
Explanation:
The commutator of the electric motor reverses the current in each half revolution to keep the torque, turning the coil in the same direction. This occurs as the north pole of the electromagnet nears the south pole of the permanent magnet, and the current reverses, which causes the poles of the magnets to repel.
Thus, the correct answer is "the north pole of an electromagnet placed in the center of a permanent magnet repels the north pole of the permanent magnet".
Answer:
The answer is D
Explanation:
Just took the test on Edge :)
What is the period of a pendulum near Earth’s surface that is 130 cm long?
Question 1 options:
2.3 s
0.83 s
9.1 s
22.9 s
Answer:
A). 2.3 s
Explanation:
Given that,
Length of the string = 130cm or 1.3 m
g near Earth's surface = 9.8 [tex]ms^{-2}[/tex]
To determine the period of a pendulum near Earth’s surface;
T = 2 π [tex]\sqrt{\frac{L}{g} }[/tex]
T = 2π[tex]\sqrt{\frac{1.3}{9.8} }[/tex]
T = 2.3 sec
Therefore, the period of the pendulum near the earth's surface is 2.3 sec.
Pls help quick too.................
Answer:
Pulley = Flag Pole
Screw = Side latch
Wedge = Scissors
Wheel and axle = Car
A car is being driven down a level track with no net force on it. This motion is best described as
A)Linear motion
B)circular motion
C) periodic motion
D) projectile motion
A)Linear motion
If there is not net force on the car, then by the Newton Second Law, the acceleration is zero, and the only valid option for zero acceleration is A).
If a wave is traveling at 200 m/s and it’s wavelength is 0.5 meters , what is the frequency of the wave
Answer:
400 Hz
Explanation:
The frequency of a sound wave is found by the velocity/wavelength. Therefore, f = v/wavelength = (200 m/s)/(0.5 m) = 400 Hz
I hope this helps! :)
Suppose that you wanted to use either conservation of momentum or conservation of kinetic energy to predict the outcome when a large car collides with a smaller car in a demolition derby. Which of the two quantities would be more appropriate for your calculation? Explain please.
Answer:
Conservation of momentum
Explanation:
Out of the two options given, the more appropriate one is the law of conservation of momentum. This is particularly so because momentum deals with the velocity or speed of the car while considering its mass. So, if a large car is to collide with another car, small one, then the momentum is what is considered. Energy on the other hand is talking about the work that is done, while the momentum considers the mass of the car while it is moving and considering its speed also
Hydropower is alternative source of energy
Answer:
Hydropower is an alternate source!Its expensive and takes up large spaces and many natural resources Takes homes of natural species.Answer:
because Hydropower is fueled by water, so it's a clean fuel source, meaning it won't pollute the air like power plants that burn fossil fuels, such as coal or natural gas. Hydroelectric power is a domestic source of energy, allowing each state to produce their own energy without being reliant on international fuel sources.
Explanation:
please mark as brainlest
Which one of the the following occurs when sodium forms an ionic bond?
Answer:
An atom of sodium (Na) donates one of its electrons to an atom of chlorine (Cl) in a chemical reaction, and the resulting positive ion (Na+) and negative ion (Cl−) form a stable ionic compound (sodium chloride; common table salt) based on this ionic bond.
Explanation:
All the info i can give you
Which type of change is freezing water an example of?
Answer:
For example, a physical change does not result in the formation of new substances. Physical changes alter only the size, shape, form or matter state of a material. Water boiling, melting ice, tearing paper, freezing water and crushing a can are all examples of physical changes.
Explanation:
Hooke's law describes a certain light spring of unstretched length 32.1 cm. When one end is attached to the top of a doorframe and a 7.94 kg object is hung from the other end, the length of the spring is 42.4 cm. (a) Find its spring constant. .7554 Correct: Your answer is correct. kN/m (b) The load and the spring are taken down. Two people pull in opposite directions on the ends of the spring, each with a force of 178 N. Find the length of the spring in this situation. .7923 Incorrect: Your answer is incorrect.
Answer:
[tex]0.75623\ \text{kN/m}[/tex]
[tex]55.6\ \text{cm}[/tex]
Explanation:
m = Mass of object = 7.94 kg
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
x = Change in length of the spring = [tex](42.4-32.1)\ \text{cm}[/tex]
F = Force on the spring
Force of gravity on the object and the force on the spring will be equal
[tex]mg=kx\\\Rightarrow k=\dfrac{mg}{x}\\\Rightarrow k=\dfrac{7.94\times 9.81}{0.424-0.321}\\\Rightarrow k=756.23\ \text{N/m}[/tex]
The spring constant is [tex]756.23\ \text{N/m}=0.75623\ \text{kN/m}[/tex]
F = 178 N
Force on spring is given by
[tex]F=kx\\\Rightarrow x=\dfrac{F}{k}\\\Rightarrow x=\dfrac{178}{756.23}\\\Rightarrow x=0.235\ \text{m}=23.5\ \text{cm}[/tex]
The length of the spring will be [tex]32.1+23.5=55.6\ \text{cm}[/tex].
What is the acceleration of gravity on Earth?
Answer:
9.807 m/s²
Explanation:
PLS make me brainliest
Answer:
[tex]\huge\boxed{\sf 9.8 \ m/s^2}[/tex]
Explanation:
The acceleration due to gravity is g the value of which is 9.8 m/s².
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807A 10-foot ladder is leaning straight up against a wall when a person begins pulling the base of the ladder away from the wall at the rate of 1 foot per second. Calculate the true distance between the top of the ladder and the ground when the base of the ladder is 9 feet from the wall.
Answer:
[tex]y = 4.36[/tex]
Explanation:
Let the height of the ladder be L
[tex]L = 10[/tex]
Also:
Let [tex]x = distance\ from\ the\ base\ of\ the\ ladder[/tex]Let [tex]y = height\ of\ the\ base\ of\ the\ ladder[/tex]When the ladder leans against the wall, it forms a triangle and the length of the ladder forms the hypotenuse.
So, we have:
[tex]L^2 = x^2 + y^2[/tex] --- Pythagoras Theorem
When the base is 9ft from the wall, this means that:
[tex]x = 9[/tex]
Substitute 9 for x and 10 for L in [tex]L^2 = x^2 + y^2[/tex]
[tex]10^2 = 9^2 + y^2[/tex]
[tex]100 = 81 + y^2[/tex]
Make [tex]y^2[/tex] the subject
[tex]y^2 = 100 - 81[/tex]
[tex]y^2 = 19[/tex]
Make y the subject
[tex]y = \sqrt{19[/tex]
[tex]y = 4.36[/tex]
Hence, the true distance at that point is approximately 4.36ft
The true statement about the true distance between the top of the ladder and the ground when the base is 9 feets from the wall is - 9/√19
Let :
x = distance from base of ladder y = Length of ladderLadder forms a right angle triangle as it leans against the wall :
Hence, we have :
Opposite² + Adjacent² = hypotenus²x² + y² = 100Taking the implicit derivative of both sides:
2xdx/dt + 2ydy/dt = 0
xdx/dt + ydy/dt = 0
ydy/dt = - xdx/dt
dy/dt = (-xdx/dt) / y
When the ladder is 9 ft from the wall;
x = 981 + y² = 100
y² = 100 - 81 = 19
y = √19
Substituting into the equation :
dy/dt = -9(1)/√19
Hence, dy/dt = - 9/√19
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Fire trucks have the word FIRE written two ways, as seen here, on the front of the truck. Why is that?
Answer:
b.
Explanation:
16. Explain the following observations:
i. Water wets glass surface but does not wet the waxed glass surface.
Answer:
because the cohesive forces within the drops are stronger than the adhesive forces between the drops and the wax. Water wets glass and spreads out on it because the adhesive forces between the liquid and the glass are stronger than the cohesive forces within the water.
Answer:
the adhesive forces between the drops are stronger than cohesive force between the liquid
What is the launch speed of a projectile that rises vertically above the Earth to an altitude equal to 14 REarth before coming to rest momentarily
Answer:
v = 1.078 10⁴ m / s
Explanation:
To solve this exercise we can use conservation of mechanical energy
Starting point. Just clearing
Em₀ = K + U = ½ m v² - G m M / [tex]R_{e}[/tex]
Final point. At r = 14R_{e}
Em_{f} = U = -G m M / 14R_{e}
how energy is conserved
Em₀ = [tex]Em_{f}[/tex]
½ m v² - G m M /R_{e} = -G m M / 14R_{e}
½ v² = G M / R_{e} (-1/14 + 1)
v² = 2 G M / R_{e} 13/14
we calculate
v² = 2 6.67 10⁻¹¹ 5.98 10²⁴ / 6.37 10⁶ 13/14
v = √ (1,16 10⁸)
v = 1.078 10⁴ m / s
The launch speed of a projectile that rises above the earth will be
v = 1.078 10⁴ m / s
What is speed?
Speed is defned as the movement of any object with respect to the time the formula of speed is given as the ratio of the distance with time.
To solve this exercise we can use conservation of mechanical energy
Starting point. Just clearing
[tex]E_{mo} = K + U = \dfrac{1}{2}m v^2 - \dfrac{G m M} { r}[/tex]
Final point. At[tex]r = 14R_{e}[/tex]
[tex]Em_{f} = U = \dfrac{-G m M }{14R_{e}}[/tex]
how energy is conserved
[tex]E_{mo }= \dfrac{1}{2} m v^2 -\dfrac{-G m M }{R_{e}} = \dfrac{-G m M }{ 14R_{e}}[/tex]
[tex]\dfrac{1}{2} v^2 = \dfrac{G M }{ R_{e} (\dfrac{-1}{14} + 1)}[/tex]
[tex]v^2 = \dfrac{2 G M} { R_{e} \dfrac{13}{14}}[/tex]
we calculate
[tex]v^2 = \dfrac{2 6.67 \times10^{-11}\times 5.98 \times 10^{24}} { 6.37 \times 10^{6} \times \dfrac{13}{14}}[/tex]
[tex]v = \sqrt{ (1,16\times 10^8)}[/tex]
v = 1.078 10⁴ m / s
Hence the launch speed of a projectile that rises above the earth will be
v = 1.078 10⁴ m / s
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Describe the role of the
nucleus in cell activities.
Answer:the nucleus controls and regulates the activities of the cell
Explanation:trust me bro
Answer:
The nucleus controls and regulates the activities of the cell and carries the genes, structures that contain the hereditary information.
Two masses sit at the top of two frictionless inclined planes that have different angles,__deleted9917f34947e1359b5705bbac0d9227f8ec5df862078213a2db19c72f00189109deleted__ 0N86-C1-52-40-A837-22820 50% Part (a) What can be said about the speeds of the two masses at the bottom of their respective paths
Answer:
v = [tex]\sqrt{2gh}[/tex]
the speed in the two planes will be the same since it does not depend on the angle of the same
Explanation:
In this exercise we are told that the two inclined planes have no friction force, so we can apply the conservation of energy for each one, we will assume that the initial height in the two planes is the same
starting point. Highest part of each plane
Em₀ = U = m g h
final point. Lowest part of each plane
[tex]Em_{f}[/tex] = K = ½ m v²
as there is no friction, the mechanical energy is preserved
Em₀ = Em_{f}
mg h = ½ m v²
v = [tex]\sqrt{2gh}[/tex]
As we can see, the speed in the two planes will be the same since it does not depend on the angle of the same
9. Two moving objects will change their motion if which of the following is true? a.There is no friction on the objects. b. The objects collide with each other. c.One object is heavier than the other. d.The objects are moving in space.
Answer:
lol
Explanation:
lolllll i need points sorry
You pull a 70-kg crate at an angle of 30° above the horizontal. If you pull with a force of 600N and the coefficient of kinetic friction is .4, how far will it move in 3 seconds?
Answer:
Explanation:
Force of friction acting on the body = μ mg cosθ
= .4 x 70 x 9.8 x cos30
= 237.63 N
component of weight = mgsinθ
= 70 x 9.8 x sin30
= 343 N
Net upward force = 600 - mgsinθ - μ mg cosθ
= 600 - 343 - 237.63
= 105.37 N
acceleration in upward direction = 105.37 / 70
= 1.5 m /s²
s = ut + 1/2 a t²
= 0 + .5 x 1.5 x 3²
= 6.75 m .
The crate will move at a distance of 1.215 m in 3 seconds.
How do you calculate the distance of motion?Given that the mass m of the crate is 70 kg and the angle above the horizontal is 30°. External force F on the crate is 600 N and the coefficient of friction is 0.4.
The friction force applied to the crate is calculated as given below.
Friction force = [tex]\mu mgcos \theta[/tex]
Where [tex]\mu[/tex] is the friction constant, g is the gravitational acceleration and [tex]\theta[/tex] is the angle above the horizontal.
Friction Force = [tex]0.4\times 70\times 9.8\times cos30^\circ[/tex]
Friction force = 237.63 N.
There is a force applied on the crate due to its weight is calculated as given below.
Force (weight component) = [tex]mgsin\theta[/tex]
Force (weight component) = [tex]70\times 9.8\times sin 30^\circ[/tex]
Force (weight component) = 343 N.
The net force applied to the crate is given below.
Net force = External force - friction force - force (weight component)
Net force F' = [tex]600 - 237.63 - 343[/tex]
Net force F' = 19.37 N.
The acceleration of the crate can be calculated as given below.
[tex]a = \dfrac {F'}{m}[/tex]
[tex]a =\dfrac {19.37}{70}[/tex]
[tex]a = 0.27 \;\rm m/s^2[/tex]
Hence the distance traveled by the crate in 3 seconds is calculated by the formula given below.
[tex]s = ut + \dfrac {1}{2} at^2[/tex]
Where, s is the distance, u is the initial velocity, a is the acceleration and t is the time of motion of the crate.
[tex]s = 0\times 3 + \dfrac {1}{2} \times 0.27 \times 3^2[/tex]
[tex]s = 1.215[/tex]
Hence we can conclude that the crate will move a distance of 1.215 m in 3 seconds.
To know more about the force, follow the link given below.
https://brainly.com/question/26115859.
How is it possible for man made things to move?
Answer:
Explanation:
Sure!
Cars do it all the time. Do you mean without some sort of guidance system, or some sort of computerized brain? That's getting a little tougher. It's possible I think, if you let some sort of timer turn it on.
A person pushes a 10 kg box from rest and accelerates it to a speed of 4 m/s with a constant force. If the box is pushed for a time of 2.5 s, what is the force exerted by the person?
The box is accelerated from rest to 4 m/s in a matter of 2.5 s, so its acceleration a is such that
4 m/s = a (2.5 s) → a = (4 m/s) / (2.5 s) = 1.6 m/s²
Then the force applied to the box has a magnitude F such that
F = (10 kg) (1.6 m/s²) = 16 N
A spring with a spring constant of 50 N/m is stretched by an extension of 2 cm. Calculate the energy in its elastic energy potential store
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I would like to know why this is the correct answer.
-The same net force is applied to two bodies. The first body acquires half of the acceleration of the second body. What is the relationship between the masses of the bodies?
*The mass of the first body is double the mass of the second body
Answer:
The mass of first body is double, since mass is double.
This is due to momentum
The same net force is applied to two bodies. The first body acquires half of the acceleration of the second body. The mass of first body is double, since mass is double.
What is momentum?In Newtonian physics, an object's mass and velocity are combined to form momentum, more precisely linear momentum and translational momentum. It has both a magnitude as well as a trajectory, making it a vector quantity. If an item has a mass of m and a velocity of v (also a vector quantity).
The kilogram metre per second (kg m/s), or newton-second inside the International System of Units (SI), is the unit used to measure momentum. The same net force is applied to two bodies. The first body acquires half of the acceleration of the second body. The mass of first body is double, since mass is double.
Therefore, the mass of first body is double, since mass is double.
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If you had to choose one device to use with the battery, what would it be? Do you think such a battery could be invented
someday? Explain
Answer:
I would choose refrigerator.
Explanation:
In my opinion, such a battery could be invented by changing the device as a low power mode. Plus, it is a must in order to decrease the CFC gas spreading through the atmosphere. That's all, thank you.
It takes 10 lb of force to stretch a spring 2 in. What is the stiffness (spring constant) of the spring
Answer:
875.59 N/m
Explanation:
From the question given above, the following data were obtained:
Force (F) = 10 lb
Extention (e) = 2 in
Spring constant (K) =?
Next, we shall convert 10 lb to Newton (N). This can be obtained as follow:
1 lb = 4.448 N
Therefore,
10 lb = 10 lb × 4.448 N / 1 lb
10 lb = 44.48 N
Thus, 10 lb is equivalent to 44.48 N
Next, we shall convert 2 in to metre (m). This can be obtained as follow:
1 in = 0.0254 m
Therefore,
2 in = 2 in × 0.0254 m / 1 in
2 in = 0.0508 m
Thus, 2 in is equivalent to 0.0508 m.
Finally, we shall determine the spring constant i.e the stiffness of the spring as follow:
Force (F) = 44.48 N
Extention (e) = 0.0508 m.
Spring constant (K) =?
F = Ke
44.48 = K × 0.0508
Divide both side by 0.0508
K = 44.48 / 0.0508
K = 875.59 N/m
Therefore the spring constant i.e the stiffness of the spring is 875.59 N/m
What is the velocity of the boat if the passenger shoots at an angle 60 with horizontal ? The mass of boat with the passenger is 100 kg ,mass of the bullet is 35g and its velocity is 400 m/s. <3
Answer:
400cos(60) = 200m/s
100(v) = 0.035(200)
v= 0.07m/s
Unpolarized light with intensity 300 W/m^2 passes first through a polarizing filter with its axis vertical, then through a second polarizing filter. It emerges from the second filter with intensity 121 W/m^2. What is the angle from vertical of the axis of the second polarizing filter?
Answer:
The angle from vertical of the axis of the second polarizing filter is 50.57⁰.
Explanation:
Given;
intensity of the unpolarized light, I₀ = 300 W/m²
intensity of emergent polarized light, I = 121 W/m²
let the angle from vertical of the axis of the second polarizing filter = θ
Apply Malus's law, intensity of emergent polarized light is given as;
I = I₀Cos²θ
[tex]Cos^2 \theta = \frac{I}{I_o} \\\\Cos^2 \theta =\frac{121}{300} \\\\Cos^2 \theta =0.4033\\\\Cos \theta = \sqrt{0.4033} \\\\Cos \theta = 0.6351\\\\\theta = Cos^{-1} (0.6351)\\\\\theta = 50.57 ^0[/tex]
Therefore, the angle from vertical of the axis of the second polarizing filter is 50.57⁰.
The weight of an object is 118N. If the object is moved to a
distance that is twice its original distance from the planet's
center, what will the new weight be?
Answer:
half the weight depending on planet gravitational force. weight wouldn't change though if gravitational force is strong
Explanation:
The highest surface temperature on any of the solar system’s planets is found on Venus. Partly because of its nearness to the sun and partly because of the extreme pressure of its atmosphere, the average daytime temperature on Venus is 453°C. What is this temperature in degrees Fahrenheit and in kelvins?
Answer:
Fahrenheit ⇒ 847.4 °FKelvin ⇒ 726.15KExplanation:
To convert Celsius to Fahrenheit, use the following formula;
= (°C * 9/5) + 32
= (453 * 9/5) + 32
= 847.4 °F
To convert Celsius to Kelvin, use the following;
= °C + 273.15
= 453 + 273.15
= 726.15K
2. What do pitch and loudness have in common?
Both are measured in decibels, or dB.
Both depend on a wave's frequency.
Both are subject to a person's interpretation.
Answer:
Both are subject to a persons interpretation
Explanation:
We hear people describe this when somebody is making an irresistible sound. usually people say the baby has a pitch scream.