Answer: Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. ... During the 1930s Bohr helped refugees from Nazism.
Two balls are thrown against a wall. Ball 1 has a much higher speed than ball 2.
Explain how the energy of the two balls is different.
Let both the balls have the same mass equals to m.
Let [tex]v_1[/tex] and [tex]v_2[/tex] be the speed of the ball1 and the ball2 respectively, such that
[tex]v_1>v_2\;\cdots(i)[/tex]
Assuming that both the balls are at the same level with respect to the ground, so let h be the height from the ground.
The total energy of ball1= Kinetic energy of ball1 + Potential energy of ball1. The Kinetic energy of any object moving with speed, [tex]v[/tex], is [tex]\frac 12 m v^2[/tex]
and the potential energy is due to the change in height is [tex]mgh[/tex] [where [tex]g[/tex] is the acceleration due to gravity]
So, the total energy of ball1,
[tex]=\frac 12 m v_1^2 + mgh\;\cdots(ii)[/tex]
and the total energy of ball1,
[tex]=\frac 12 m v_2^2 + mgh\;\cdots(iii)[/tex].
Here, the potential energy for both the balls are the same, but the kinetic energy of the ball1 is higher the ball2 as the ball1 have the higher speed, refer equation (i)
So, [tex]\frac 12 m v_1^2 >\frac 12 m v_2^2[/tex]
Now, from equations (ii) and (iii)
The total energy of ball1 hi higher than the total energy of ball2.
What are 3 ways a car can accelerate? (CRE)
The three ways a car can accelerate are change in velocity, change in direction, or both.
What is acceleration?The rate of velocity change concerning time is known as acceleration. The acceleration of the object is;
[tex]\rm a = \frac{v-u}{t}[/tex]
Here,
a is the acceleration
v is the final velocity
u is the initial velocity
t is the period
The three ways a car can accelerate are as follows;
a)Change in velocity.
b)Change in direction
c)Change in both velocity and direction.
Hence, the three ways a car can accelerate are change in velocity, change in direction, or both.
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URGENT URGENT DUE SOON!!
Which statement describes a question that can guide the design of a
scientific investigation?
A. It asks about a cause-and-effect relationship between two
variables.
B. It asks about the preferred outcome of the investigation.
C. It asks about whether a controlled variable is necessary.
D. It asks about how the observations will be organized.
Answer:
A.
Explanation:
Im just guessing because it sounds like it describes a hypothesis the most and you said its urgent
The position of a particular particle as a function of is given by r=(8.5t i+5.6j-2tk )m (a) Determine the particle’s velocity and acceleration as a function of time.
(b) Find the instantaneous velocity and acceleration of the particle at t=3.0 s.
Answer:
use google to find answer
Explanation:
69 69 69 69 69 69
The current in an electric hair dryer is 12A. How many electrons flow through the hair dryer in 5.2 min ?
"Ampere" means 1 coulomb of charge every second.
12A means 12 coulombs of charge every second.
5.2 minutes = (5.2) x (60 seconds) = 312 seconds
12A for 312 seconds means (12) x (312) = 3,744 coulombs of charge
1 coulomb is the amount of charge carried by 6.24 x 10¹⁸ electrons .
So 12A for 312 seconds means (3,744) x (6.24 x 10¹⁸) electrons.
That's 2.336 x 10²² electrons .
or 23,360,000,000,000,000,000,000 electrons .
(rounded to the nearest 10 quintillion).
Describing the Motion of an Object
SARE
Use the information from the graph to answer the
question.
What is the acceleration of the object?
m/s2
Velocity vs. Time
Velocity (m/s)
45
40
35
30
25
20
10
5
0
0
2
10
12
4. 6 8
Time (s)
Answer:
i actually dont know im so sorry but i will keep trying to find the answerr
A driver looks down at their speedometer and sees they are moving at 45 mph. This measurement would be a
Answer:
This measurement would be a measure of the speed of an object(the car ) in motion
Explanation:
A driver looks down at their speedometer and sees they are moving at 45 mph. This measurement would be about the speed of the car or about how fast the car is moving.
This means, the car is travelling the distance of 45 miles in every hour.
This measurement would also be about the instantenous speed of the car which is 45mph.
Problem 1: If a car is traveling at a speed of 28.0 m/s,
is it exceeding the speed limit of 55.0 mi/h?
Answer:
Yes, see explanation.
Explanation:
Hello,
In this case, considering that 1 hour equals 3600 seconds and 1 mile equals 1609.34 meters, the speed at which the car is moving is:
[tex]28.0\frac{m}{s} *\frac{1mi}{1609.34m}*\frac{3600s}{1h} \\ \\=62.63\frac{mi}{h}[/tex]
Thus, since the speed is greater than the limit we conclude it is exceeding the speed limit.
Regards.
which is an example of a vector quantity
A.time
B.speed
C. acceleration
D. distance
Answer:
The answer to your question is C
Explanation:
acceleration is a vector quantity because it has both magnitude and direction
Translate the following sentence into an equation. "The distance traveled is the speed multiplied by the time." a) d = v * t a) d = v * t b) Δx = v * Δt c) v = d/t d) d=Δx*t
The correct answer is A) d = v * t
Explanation:
When writing an equation the goal is to represent the equality between different mathematical expressions or elements. Due to this, in an equation the symbol = is always used. Additionally, to translate a sentence into an equation, the variables should be represented using numbers or letters.
For example, in the sentence "The distance traveled is the speed multiplied by the time" there are three variables mentioned: distance, speed, and time. Also, these can be represented through the letters d (distance), v (speed or velocity), and t (time). Besides this, the sentence explains speed should be multiplied by time, which means it should be written as v × t or v * t and this is equivalent (=) to distance or t. According to this, the final equation would be d = v * t.
Acceleration occurs when velocity changes. O True O False
Answer:
True
Explanation:
Acceleration by definition is the change in velocity divided by the change in time. Thus when the velocity changes, there must be an acceleration.
NEED HELP FAST!!
As the air on the surface of the Earth warms, what happens to the density of the air?
A.It decreases
B.It increases
C.It remains constant
D.It decreases, then increase
Answer:
B
Explanation:
because when the air rises the density increases
We want to predict what will happen to the density of the air on the surface of the Earth when it warms up.
We will see that the correct option is D: "It decreases, then increases"
We know that the temperature of a given object (in this case a mass of air) is related to the kinetic energy of the particles that conform it.
As the temperature increases, the kinetic energy also increases, thus, the amount of motion of each particle increases, thus, the volume of the object increases.
Now remember that:
density = Mass/Volume.
So if the volume of something increases, we will see that the density decreases (as the volume is in the denominator).
Then if the temperature of the air increases, we will see that the density of the air in the surface decreases.
But it does not end there, as only the air near the surface suffers this change of density, we will have a denser mass of air (colder air) above it. And because it is denser (has more mass in the same volume) we can say that it is heavier.
Then eventually the hot air will rise, and the cold air will fall down, thus the density of the air in the surface increases again, as the colder and denser air comes near the surface.
This is one way of how wind currents are born.
Concluding we can see that the correct option is D: "It decreases, then increases"
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Which term describes the tendency of an object to resist changes in motion?
A) reaction
B) force
C) inertia
D) acceleration
Answer:
inertia
Explanation:
A 6.0-μF air-filled capacitor is connected across a 100-V potential source (a battery). After the battery fully charges the capacitor, it is left connected and the capacitor is immersed in transformer oil, which has a dielectric constant of 4.5. How much additional charge flows from the battery onto the capacitor during this process? Group of answer choices
Answer:
Change in Q = 2.1x 10^-3 C
Explanation:
We are given that
The Initialcapacitance C1 = 6.0μF
Initial charge oncapacitor
Q1 = C1 V
= 6.00 x 10^-6 x 100
= 6.00 x 10^-4 C
So the Final capacitance C2 will be
= K x C1 = 4.5 x 6.00 x 10^-6
= 2.7 x 10^ -5 F
So to get Finalcharge
We use Q2 = C2 x V
= 2.7 x 10^ - 5 x 100
= 27 x 10^ -4 C
So Charge flown in thecapacitor is change in Q
Which is = Q2 - Q1
= 27 x 10^-4 - 6.0 x 10^ -4
Change in Q = 2.1x 10^-3 C
Using the equation for for Newton's Second law, m=F/a solve the following problem. You have been given an object with a force of 10N and an acceleration of 2 m/s2, what is the mass?
Group of answer choices
1. 8g
2. 3g
3. 20g
4. 5g
Answer:
4. 5g
Explanation:
F=ma so, m=Fa. All you have to do is 10/2. Don't be confused by the units. Mass will normally be in grams.
What is the total electric charge of 2.5 kg of (a) electrons and (b) protons?
Answer:
a
[tex]Q_e = -4.39 *10^{11} \ C [/tex]
b
[tex]Q_p = + 2.395*10^{-8} \ C [/tex]
Explanation:
Generally the number of electron in the given mass is mathematically evaluated as
[tex]N_e = \frac{2.5}{m_e }[/tex]
Here m_e is the mass of electron with value [tex]m_e = 9.11 * 10^{-31} \ kg[/tex]
=> [tex]N_e = \frac{2.5}{ 9.11 * 10^{-31} }[/tex]
=> [tex]N_e =2.74 *10^{30} \ electrons [/tex]
The total electric charge is mathematically represented as
[tex]Q_e = N_e * e[/tex]
Here e is the charge on a single electron with value [tex]e = 1.60 *10^{-19} \ C[/tex]
So
[tex]Q_e = -2.74 *10^{30} * 1.60 *10^{-19} [/tex]
[tex]Q_e = -4.39 *10^{11} \ C [/tex]
The negative sign is because we are considering electron
Generally the number of protons in the given mass is mathematically evaluated as
[tex]N_p = \frac{2.5}{m_p }[/tex]
Here m_p is the mass of electron with value [tex]m_e = 1.67 * 10^{-27} \ kg[/tex]
=> [tex]N_p = \frac{2.5}{ 1.67 * 10^{-27} }[/tex]
=> [tex]N_p =1.497 *10^{27} \ protons [/tex]
The total electric charge is mathematically represented as
[tex]Q_p = + N_p * e[/tex]
Here p is the charge on a single proton with value [tex]p = 1.60 *10^{-19} \ C[/tex]
So
[tex]Q_p = +1.497 *10^{27} * 1.60 *10^{-19} [/tex]
[tex]Q_p = + 2.395*10^{-8} \ C [/tex]
Which of the following is not a type of kinetic energy
ball is thrown vertically upward from an initial position 5m above the ground. At the same time, a cube is released from rest down aslippery incline, from an unknownheight. The two objects reach the ground at the same instant, and both have a final speed of 15m/s. What is the angle ofthe incline
Answer:
The value is [tex]\theta = 34.8 ^o[/tex]
Explanation:
Generally the time it takes the ball to move from maximum height to the ground is
[tex]t = \frac{v - u}{g}[/tex]
Here u= 0 m/s and v = 15 m/s
So
[tex]t = \frac{15 - 0}{9.8}[/tex]
=> [tex]t = 1.53 \ s [/tex]
Generally the maximum height traveled in time t is mathematically represented as
[tex]s = u * t + \frac{1}{2} * g * t^2[/tex]
=> [tex]s = 0 * 1.53 + \frac{1}{2} * 9.8 * 1.53^2[/tex]
=> [tex]s = 11.5 \ m [/tex]
The interval in distance between the maximum height and the initial position of the ball is
[tex]d = s - k[/tex]
Here k = 5 m (given)
[tex]d = 11.5 - 5[/tex]
[tex]d = 6.5 \ m [/tex]
Generally from the kinematic equation we have that
[tex]d = ut_1 + \frac{1}{2} g * t_1 ^2[/tex]
Here [tex] t_1 [/tex] is the time taken to travel through d
[tex]t_1 = \sqrt{ \frac{2 * d }{g} }[/tex]
=> [tex]t_1 = \sqrt{ \frac{2 * 6.5 }{9.8} }[/tex]
=> [tex]t_1 = 1.15 \ s [/tex]
Generally the total time for this fight is mathematically represented as
[tex]t_f = t + t_1[/tex]
=> [tex]t_f = 1.15 + 1.53[/tex]
=> [tex]t_f = 2.68 \ s [/tex]
Generally the vertical force exerted on the cube is mathematically represented as
[tex]F = m * g * sin (\theta )[/tex]
=> [tex] m * a = m * g * sin (\theta )[/tex]
=> [tex] a = g * sin (\theta )[/tex]
Now a is mathematically represented as
[tex]a = \frac{v - u }{t_f}[/tex]
=> [tex]a = \frac{15 - u }{2.68}[/tex]
=> [tex]a = 5.597 \ m/s^2[/tex]
So
[tex] 5.597 = 9.8 * sin (\theta )[/tex]
[tex]\theta = sin^{-1} [\frac{5.597}{9.8} ][/tex]
[tex]\theta = 34.8 ^o[/tex]
a torch battery produces electricity from – energy
Answer:
First, the batteries contain chemical energy, which is energy that is released during a chemical change. When chemical bonds are formed or broken, electrons are rearranged, and this movement of electrons produces chemical energy. Batteries can convert stored chemical energy into electrical energy.
chemical energy
why is force required to move an object
Answer:
Force is the push or pull exerted on an object to make it move.
Without force , an object will remain in it's position
Newton's first law of motion proves this. And it states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
Explanation:
Newton's second law of motion describes how force is related to mass and acceleration, and this relationship is used to calculate force. In general, the greater the mass of the object, the greater the force needed to move that object.
Which is a benefit of using synthetic polymers, such as nylon?
Synthetic polymers are lightweight.
O Synthetic polymers are produced in small
quantities.
Synthetic polymers are biodegradable.
Synthetic polymers are inexpensive to recycle.
Answer: Synthetic polymers are lightweight.
Explanation:
A benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
A polymer is a molecule composed of many repeating subunits.
Synthetic polymers are artificial polymers created by humans.
Most of the synthetic polymers are not biodegradable (unlike natural fibers such as cotton).
Synthetic polymers are classified according to their use into plastics, elastomers and synthetic fibers.
The advantages of synthetic polymers include: hard to break, being lightweight, and they last for a long time.
In conclusion, a benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
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If all other things remain equal, which of the following changes to a closed circuit
would result in increased resistance to the flow of electric current?
Reducing the temperature of the conductor
Reducing the thickness of the conductor
Replacing the conductor with a more conductive material
Reducing the length of the conductor
Answer:
the answer is b reducing the thickness of the conductor
Explanation:
The resistance to electric current increases as the cross-section of the conductor is reduced, as the conductor is lengthened, and as the conductor is heated. Replacing the conductor with a less-conductive material increases the resistance as well.
Answer:
Reducing the thickness of the conductor
Explanation:
The relatively high resistivity of dry skin, about 1 × 106 O·m, can safely limit the flow of current into deeper tissues of the body. Suppose an electrical worker places his palm on an instrument whose metal case is accidentally connected to a high voltage. The skin of the palm is about 1.5 mm thick. Estimate the area of skin on the worker’s palm that would contact a flat panel, then calculate the approximate resistance of the skin of the palm.
Answer:
The area is [tex]A = 0.015 \ m^2 [/tex]
The resistance is [tex]R = 1.0 *10^{5} \ \Omega [/tex]
Explanation:
From the question we are told that
The relativity of dry skin is [tex]\rho = 1 * 10^6\ \Omega\cdot m[/tex]
The thickness of the skin is [tex]d = 1.5 \ mm = 1.5 *10^{-3} \ m[/tex]
Generally the area of a flat palm with length = 0.10 m and breath b = 0.15 m is mathematically represented as
[tex]A = d * L[/tex]
[tex]A = 0.10 * 0.15 [/tex]
[tex]A = 0.015 \ m^2 [/tex]
Generally the resistance is mathematically represented as
[tex]R = \frac{\rho * d}{ A }[/tex]
=> [tex]R = \frac{ 1.0 *10^{6} * 1.5*10^{-3}}{ 0.015 }[/tex]
=> [tex]R = 1.0 *10^{5} \ \Omega [/tex]
Which of the following is not one of the emotional expressions that are universally recognized?
OA. Happiness
OB. Disgust
OC. Sadness
OD. Love
HELPP!
Answer:
B
Explanation:
The answer should be B.
a battery-operated car moves forward as a result of which device?
Answer:
the wheels
Explanation:
Answer:
depends..
Explanation:
it can be Electromagnet or generator or a motor
20. Convert 36 km/hr to m/s.
If you push a book 1.5 m across a table using a constant force of 10.0 N, how much work do you
do on the book?
Answer:
The answer is
15.0 JExplanation:
To calculate the work done by a body we use the formula
work done = force × distanceFrom the question
force = 10 N
distance covered = 1.5 m
So the work done is
work done = 10 × 1.5
We have the final answer as
15.0 JHope this helps you
The bird that migrates the farthest is the Arctic tern. Each year, the Arctic tern travels
32,000 km between the Arctic Ocean and the continent of Antarctica. Most of the
migration takes place within two four-month periods each year. Assume an Arctic
tern completes the second half of its annual migration distance in 122 days. Also
assume that during this time the tern flies directly north. If the tern flies the same
distance each day, what is its velocity in kilometers per day?
Answer: 131.14km per day
Explanation: since the second half of the terns migration takes 122 days we can assume that the full migration would take 244 days. using this we can divide the total distance by the total amount of days it takes (because speed = distance/time) which is 32,000/244, which would be 131.14
Enunciado: Una bola se lanza verticalmente de la parte superior de un edificio con una velocidad inicial de 25 m/s. La bola impacta al suelo en la base del edificio 7 segundos después de ser lanzada. (Marque la respuesta correcta)
¿Qué altura subió la bola (medida desde la parte superior del edificio)? a) 19.6 m b) 12.75 m c) 31.88 m d) 40 m e) 20 m
Responder:
Explicación:
Usaremos la ecuación de movimiento para determinar la altura de la bola medida desde la parte superior del edificio.
Usando la ecuación para obtener la altura de caída
S = ut + 1 / 2gt²
u es la velocidad inicial = 25 m / s
g es la aceleración debida a la gravedad = 9,81 m / s²
t es el tiempo = 7 segundos
S es la altura de la caída
S = 25 (7) +1/2 (9,81) × 7²
S = 175 + 4,905 (49)
S = 175 + 240,345
S = 415,35 m
Esto significa que la pelota se elevó a 415,35 m de altura
La altura vertical máxima alcanzada es de 31,88 m.
Tenemos la siguiente información de la pregunta;
Velocidad inicial = 25 m/s
Velocidad final = 0 m/s (a la altura máxima)
tiempo empleado = 3,5 minutos (el tiempo empleado para subir y bajar es igual).
Usando la ecuación;
v^2 = u^2 - 2gh
Dado que v = 0
u^2 = 2gh
h = tu^2/2g
h = (25)^2/2 *9.8
h = 31,88 m
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Car wheel's slip in mud. why?
Answer:
Because its wet
Explanation: