Answer:
3
Explanation:
because
A car approaches a pedestrian standing on the side of the road. The car is traveling at 24.2 m/s. The horn of the car emits a sound wave with a frequency of 482 Hz. What frequency is heard by the pedestrian
Final answer:
The frequency heard by the pedestrian as the car approaches, using the Doppler Effect, would be approximately 518 Hz.
Explanation:
To determine the frequency heard by the pedestrian as the car approaches, we use the Doppler Effect equation:
f' = f(v + v0)/(v - vs)
where:
f' is the frequency heard by the observer (pedestrian)
f is the frequency of the source (car horn's frequency)
v is the speed of sound
v0 is the speed of the observer (pedestrian, which is 0 m/s since they are standing)
vs is the speed of the source (car)
Given the car horn's frequency, f = 482 Hz, and the car's speed, vs = 24.2 m/s. Assuming the speed of sound on a standard day (approximately 343 m/s), the equation modifies to:
f' = 482(343 + 0)/(343 - 24.2)
We can now calculate:
f' = 482(343)/(318.8) ≈ 518 Hz
The frequency heard by the pedestrian would be approximately 518 Hz when the car is approaching.
3. This diagram shows that Al can see the reflections of Ed and Fred in the
mirror. Which two students can both see the reflections of Cy, Di, Ed and
Fred? *
For
Answer:
Only Cy and Di could see the reflections.
Explanation:
Reflection is a property of light that makes it to travel through its initial path on hitting a plane surface. It is good to note that the angle of the incident ray to the surface is equal to the angle of reflection after hitting the surface. It can generally be classified into diffuse and specular.
A ray of light travels on a straight path, the images of the students are formed due to reflection of light at the plane surface. By ray constructions and observation, it would be observed that only Cy and Di could see the reflections of the four students. This is due to their positions with respect to the reflecting surface.
You are in your car at rest when the traffic light turns green. You place your coffee cup on the horizontal dash and hit the gas. The coffee cup does not slide as you accelerate forward. The work done by friction on your coffee cup is
Answer:
[tex]\mu mgd[/tex]
Explanation:
In the situation described in the problem, there are 3 forces acting on the coffee cup:
- The weight of the cup, acting downward
- The normal force exerted by the horizontal dash on the cup, acting upward
- The force of friction, acting forward and "keeping" the cup travelling together with the car, without sliding backward
For the purpose of this problem, we ignore the weight and the normal force, since they cancel each other out.
The force of friction here pushes the cup forward, allowing it to move together with the dash and the car, without sliding. The magnitude of this force of friction is
[tex]F_f = \mu mg[/tex]
where
[tex]\mu[/tex] is the coefficient of static friction between the cup and the dash
m is the mass of the cup
g is the acceleration of gravity
Since the cup is moving forward together with the car, it means that it has a certain displacement [tex]d[/tex], and therefore the force of friction is performing work, equal to the product between force and displacement, so:
[tex]W=F_f \cdot d = \mu mg d[/tex]
What is the distinction between glass transition temperature and melting temperature?
Answer:
Glass transition temperature is a characteristic of soda lime glass and melting temperature is for a Borosilicate glass.
Explanation:
The glass transition is the change of an amorphous solid from soft and flexible to glass-like, i.e. hard and brittle. On the other hand, the melting temperature is the temperature at which the liquid - solid phase transition occurs in a crystalline substance.
What three changes in motion show that an object is accelerating?
Answer:
There are three ways an object can accelerate: a change in velocity, a change in direction, or a change in both velocity and direction.
Explanation:
The three changes in motion show that an object is accelerating are,
a = ∆v / ta = F / ma = w²rWhat are the changes happened in an object?An object is accelerating with the changes in motion are,
1. If the velocity is increasing.
From equation of motion
a = ∆v / t
So, if the velocity increases with time, the acceleration increases. But if it decreases with time, it decelerating.
2. Also, from newton second law,
F = ma
a = F / m
Where a = acceleration
F is force applied
m is the mass
So, if the force is increase and the mass is reduced, then the acceleration is increase.
3. Also, in Circular motion,
a = w²r
Where,
a is linear acceleration
w is angular speed
r is the radius.
So, when the angular speed is increased, then the linear acceleration is increased.
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What other theory does the author compare to the Big Bang to?
Answer:
The two Russian authors based their exposition on what they called the Friedmann theory of a singular beginning of the universe, referring throughout to the “theory of the hot universe” as an alternative to the hot Big Bang theory.
This diagram shows that Al can see the reflections of Ed and Fred in the mirror. Which two students can both see the reflections of Cy, Di, Ed and Fred? *
Answer:
Cy and Di
Explanation:
We cannot tell exactly where the right end of the mirror is, but if we assume it is short of allowing Ed and Fred to see each other, we have the following:
Cy can see Cy and everyone to the right
Fred can see Di and everyone to the left
The only two that can see all of Cy, Di, Ed, and Fred are Cy and Di.
_____
If the mirror extends far enough to the right for Ed to see Fred, then all of Cy, Di, and Ed can see the four folks of interest.
Answer:
Cy and Di
Explanation:
Which of the following is not an effect of climate change?
Rising sea levels
Coastal flooding
Increased glacial ice
Extreme weather
what is an incident wave,and a normal
Answer:
An incident wave is a current or voltage wave that travels through a transmission line from the generating source towards the load. It becomes incident when it arrives at a discontinuity or another medium with different propagation characteristics. Wave normal. A unit vector which is perpendicular to an Equiphase surface of a wave, and has its positive direction on the same side of the surface as the direction of propagation.
Explanation:
Answer:
A current or voltage wave that is traveling through a transmission line in the direction from source to load.
Explanation:
Hope this helps!
Two resistances, R1 and R2, are connected in series across a 9-V battery. The current increases by 0.450 A when R2 is removed, leaving R1 connected across the battery. However, the current increases by just 0.225 A when R1 is removed, leaving R2 connected across the battery. a) Find R1 b) Find R2
Answer:
a. R1 = 0.162 Ω
b. R2 = 0.340 Ω
Explanation:
Since the resistors R1 and R2 are connected in series, the current flowing through them when the 9 V battery is applied is 9/R1 + R2.
When the current increases by 0.450 A wen only R1 is in the circuit, the current is
9/R1 + R2 + 0.450 A = 9/R1 (1)
When the current increases by 0.225 A when only R2 is in the circuit, the current is
9/R1 + R2 + 0.225 A = 9/R2 (2)
equation (1) - (2) equals
9(1/R1 - 1/R2) = 0.450 A - 0.225
9(1/R1 - 1/R2) = 0.125
(1/R1 - 1/R2) = 0.125 A/9 = 0.0138
1/R1 = 0.0138 + 1/R2
R1 = R2/(1 + 0.0138R2) (3)
From (1)
9/R1 - 9/R1 + R2 = 0.450 A
9R2/[R1(R1 + R2)] = 0.450 A
R2/[R1(R1 + R2)] = 0.450 A/9 = 0.5
R2/[R1(R1 + R2)] = 0.5 (4)
From (3) R2/R1 = (1 + 0.0138R2) and from (4) R2/R1 = 0.5(R1 + R2). So,
(1 + 0.0138R2) = 0.5(R1 + R2)
0.5R1 + 0.5R2 = 1 + 0.0138R2
0.5R1 = 1 + 0.0138R2 - 0.5R2
0.5R1 = 1 - 0.4862R2 (5)
Substituting (3) into (5) we have
0.5R2/(1 + 0.0138R2) = 1 - 0.4862R2
R2 = (1 + 0.0138R2)(1 - 0.4862R2)
R2 = 1 - 0.4724R2 - 0.0067R2²
Collecting like terms, we have
0.0067R2² + 0.4724R2 + R2 - 1 = 0
0.0067R2² + 1.4724R2 - 1 = 0
Using the quadratic formula,
[tex]R_{2} = \frac{-1.4724 +/-\sqrt{(1.4724)^{2} - 4 X 0.0067 X -1} }{2 X 0.0067} \\= \frac{-1.4724 +/-\sqrt{2.1680 + 0.0268} }{0.0268}\\= \frac{-1.4724 +/-\sqrt{2.1948} }{0.0268}\\= \frac{-1.4724 +/- 1.4815 }{0.0268}\\= \frac{-1.4724 + 1.4815 }{0.0268} or \frac{-1.4724 - 1.4815 }{0.0268}\\= \frac{0.0091 }{0.0268} or \frac{-2.9539}{0.0268}\\= 0.340 or -110.22[/tex]
We choose the positive answer.
So R2 = 0.340 Ω
From (5)
R1 = 0.5 - 0.9931R2
= 0.5 - 0.9931 × 0.340
= 0.5 - 0.338
= 0.162 Ω
a. R1 = 0.162 Ω
b. R2 = 0.340 Ω
In an arcade game a 0.144 kg disk is shot across a frictionless horizontal surface by compressing it against a spring and releasing it. If the spring has a spring constant of 164 N/m and is compressed from its equilibrium position by 7 cm, find the speed with which the disk slides across the surface.
Answer:
The speed with which the disk slides across the surface is 2.36 m/s.
Explanation:
Given that,
Mass of the disk, m = 0.144 kg
Spring constant of the spring, k = 164 N/m
The spring is compressed from its equilibrium position by 7 cm or 0.07 m
We need to find the speed with which the disk slides across the surface. It is a case of conservation of energy in which the energy of the spring is gained by its kinetic energy. It is given by :
[tex]\dfrac{1}{2}kx^2=\dfrac{1}{2}mv^2[/tex]
v is speed of the disk.
[tex]kx^2=mv^2\\\\v=\sqrt{\dfrac{kx^2}{m}} \\\\v=\sqrt{\dfrac{164\times 0.07^2}{0.144}} \\\\v=2.36\ m/s[/tex]
So, the speed with which the disk slides across the surface is 2.36 m/s.
using a cathode ray tube , what did Thomson confirm
Answer:
Its b
Explanation:
If ur on edgenuity!!
What is the relationship between heavy objects and inertia
Answer:
Inertia is the measure of mass of a body which means that grater the mass grater will be the inertia.
The relationship between heavy objects and inertia is heavy objects have more inertia than lighter objects. The correct option is b.
The ability or propensity of an object to resist changes in motion is known as inertia. An object's mass is how much matter there is inside of it, and heavier objects have more mass than lighter ones.
The mass of an object has an impact on inertia. More mass means an object has more inertia, which makes it more resistant to changes in motion.
Both physical items and human minds exhibit inertia, which can support aversion to change and the preservation of habituated behaviours.
It is true that heavier items have more inertia than lighter ones in terms of their relative weights.
Thus, the correct option is b.
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Your question seems incomplete, the probable complete question is:
What is the relationship between heavy objects and inertia?
a. Heavy objects have less inertia than lighter objects.
b. Heavy objects have more inertia than lighter objects.
c. Heavy objects have the same amount of inertia as lighter objects.
d. The relationship between heavy objects and inertia is not defined.
The roller coaster from problem #1 then tops a second hill at 15.0 m/s, how high is the second hill?
Problem #1: A roller coaster glides from rest from the top of an 80.0 meter hill. What is the speed of the roller coaster at the bottom of the hill?
To find the height of the second hill, we can use the conservation of mechanical energy principle.
Explanation:To find the height of the second hill, we can use the conservation of mechanical energy principle. At the top of the second hill, the roller coaster has a kinetic energy and a gravitational potential energy. The total mechanical energy at the top of the hill is equal to the total mechanical energy at the bottom of the first hill. We can set up the equation:
mgh + 0.5mv^2 = mgh2
where m is the mass of the roller coaster, g is the acceleration due to gravity, h is the height of the first hill, v is the speed at the bottom of the hill, and h2 is the height of the second hill. Substituting the given values into the equation will give us the height of the second hill.
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Final answer:
When a roller coaster tops the second hill at 15.0 m/s, the height of the hill can be calculated by rearranging the conservation of energy equation. By setting the kinetic energy equal to the potential energy, we can solve for the height of the hill.
Explanation:
The question relates to the conservation of energy in physics, specifically within the context of a roller coaster. We are looking to find how high the second hill is, knowing that the roller coaster tops it at 15.0 m/s.
First, let's solve problem #1 as reference: A roller coaster starting from rest on an 80.0 meter hill without friction will convert its potential energy entirely into kinetic energy at the bottom. The formula to calculate the final speed (v) at the bottom is given by v = √(2gh), where g is the acceleration due to gravity (9.8 m/s²) and h is the height. Substituting the given values, we find the final speed at the bottom of the first hill.
For the second part, the roller coaster tops the second hill at 15.0 m/s, which is the kinetic energy at that point. To find the height of the second hill, we'll set that kinetic energy equal to the potential energy at the top of the hill.
The formula rearranged to solve for the height (h) is h = v₂ / (2g). When we input the speed and acceleration due to gravity, we can determine the height of the second hill.
The vapor pressure of any substance at its normal boiling point is
Answer: one atmosphere!
Explanation: The normal boiling point of a liquid is the temperature at which its vapor pressure is equal to one atmosphere (760 torr). I hope this answers your questionl.
The vapor pressure refers to the force created by a gas in the confined container that is in balance with a liquid or a solid at a particular temperature. The vapor pressure of any substance at its normal boiling point is 1 Atm.
What is Boiling Point?When a liquid reaches its boiling point, which occurs at a degree where the pressure that the environment and the liquid's vapor impose on it are equal, the liquid turns into its vapor without increasing the temperature.
Until the pressure imposed by the vapor reaches a specific amount known as the pressure of the fluid at that temp, a liquid partially evaporates into the air above it at any temperature.
When a liquid reaches its boiling point, vapor bubbles start to form within it and ascend to the surface as the temperature rises, increasing the evaporation rate.
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A student wants to determine whether an unknown solid is an ionic compound. He puts some in water and finds that it does not dissolve. He says that this proves the solid is ionic. Which best evaluates the student's reasoning? (2 points) He is incorrect, because water can dissolve ionic solids. The test proves nothing, because water dissolves all solids. He is correct, because polar liquids cannot dissolve ionic solids. The test proves nothing, because it only shows that the solid is a compound.
Answer:
b
Explanation:
Use the drop-down menus to complete the sentences describing the important ideas in Hess’s theory.
Hess expanded on Wegener’s theory of (blank).
possible answers: Pangaea landmass, continental drift, or conveyor belt.
Hess proposed the idea that (blank) are places where crust is created.
possibles answers: mid-ocean ridges, continents, or deep-ocean trenches
Answer:
Use the drop-down menus to complete the sentences describing the important ideas in Hess’s theory.
Hess expanded on Wegener’s theory of
Continental drift .
.
Hess proposed the idea that
mid-ocean ridges are places where crust is created.
Explanation:
Hess expanded on Wegener's theory of continental drift.
Hess proposed the idea that mid-ocean ridges are places where crust is created.