Answer:
150 kJ
Explanation:
Applying,
ΔH = Energy level of Product(E') - Energy level of reactant(E)
Where ΔH = enthalpy change, E' and E = energy level of the product and the reactant respectively
ΔH = E'-E............. Equation 1
From the diagram,
Given: E' = 200 kJ, E = 50 kJ
Substitute these values into equation 1
ΔH = 200-50
ΔH = 150 kJ
Hence the enthalpy change for the reaction is 150 kJ
From class, weight is a measurement of the force of
acting on an object.
Friction
Normal
Gravity
Tension
Applied
Answer:
the answer is well known as gravity
URGENT A student runs at 4.5 m/s [27° S of W] for 3.0 minutes and then he turns and runs at 3.5 m/s [35° S of E] for 4.1 minutes. a. What was his average speed? b. What was his displacement? PLEASE SHOW ALL WORK
Answer:
Explanation:
As far as the displacement goes, we have 2 displacement vectors. If we didn't have the angles to deal with, this would be a much simpler process, but then that wouldn't be any fun at all, would it? I'll deal with the average speed first, then the displacement, which is a vector addition problem.
The average speed is found by adding together the distances the student traveled and then dividing this sum by the total time he spent traveling. If we are told that the student runs at 4.5 m/s for 3.0 minutes, we can use this to find out the distance he ran during that time interval. However, the units are not the same. We will find the distance the student traveled by convering the time to seconds.
3.0 minutes = 180 seconds, and
4.1 minutes = 246 seconds.
That means that the distance he ran in 180 seconds is found by multiplying this time be the speed at which he ran:
4.5 m/s(180 s) = 810 m and
3.5 m/s(246 s) = 860 m (rounded to follow the rules of sig dig).
This makes the speed equation look like this:
[tex]s=\frac{810+861}{180+246}=\frac{1671}{426}=3.9\frac{m}{s}[/tex] That's the average speed, which is NOT at all the same as the displacement. Displacement is where he ended up in reference to where he started. The angles play a huge part in this math (that is very involved, to say the least). We begin by restating the displacement of each "leg" of this journey.
The first leg took him 810 m at 207 degrees and
the second leg took him 860 m at 325 degrees
To find the x and y components of these 2 legs, or parts, we have to use the cos and sin formulas. We will call the first leg A and the second leg B. First the x components of both A and B:
[tex]A_x=810cos207[/tex] and
[tex]A_x=-720[/tex]
[tex]B_x=860cos325[/tex] and
[tex]B_x=704[/tex] and we add these to get the x-component of the resultant vector, C:
-720
+ 704
-10 (rounded, as needed, to the tens place).
Now for the y-components of the resultant vector:
[tex]A_y=810sin207[/tex] and
[tex]A_y=-370[/tex]
[tex]B_y=860sin325[/tex] and
[tex]B_y=-490[/tex] and we add these to get the y-component of the resultant vector, C:
-370
+ -490
-860
Since the x component is negative and so is the y, we are in QIII, so when we finally find our angle, we will have to add 180 to it.
For the magnitude of the displacement vector, in m:
[tex]C_{mag}=\sqrt{(-10)^2+(-860)^2}[/tex] which gives us
[tex]C_{mag}=860m[/tex]
Now, because displacement is vector, we also need the angle. We find that is the formula
[tex]\theta=tan^{-1}(\frac{C_y}{C_x})[/tex] and filling in:
[tex]\theta=tan^{-1}(\frac{-860}{-10})=90[/tex] (rounded correctly), and then we add 180 to give us a final direction of 270 degrees.
So the final displacement of the student is 860 m at 270 degrees
When the E string of a guitar (frequency 330 Hz) is plucked, the sound intensity decreases by a factor of 2 after 4 s. Determine
Answer:
[tex]Q=50.3[/tex]
Explanation:
From the question we are told that:
Frequency [tex]F=330Hz[/tex]
Sound intensity drop [tex]I_d=2[/tex]
Time [tex]T=4s[/tex]
Therefore
Sound intensity Ratio
[tex]\frac{I}{I_x}=\frac{1}{2}[/tex]
Generally the equation for Sound intensity is mathematically given by
[tex]\frac{I}{I_x}=e^{-4\ \=t}[/tex]
[tex]\frac{1}{2}=e^{-4\ \=t}[/tex]
[tex]\=t =5.8s[/tex]
Generally the equation for Quality Factor is mathematically given by
[tex]Q=2 \pi\frac{E}{\triangle E}[/tex]
[tex]Q=2 \pi\frac{E}{\frac{E}{2*4}}[/tex]
[tex]Q=50.3[/tex]
A student is investigating the affect of different salts on melting points. Four patches of ice of equal
size are roped off and a
different type of salt is poured on each, one receives table salt (NaCl), one
receives Calcium Chloride (CaCl2), one receives Potassium Carbonate (KCO3) and the fourth
receives inert sand instead. Each patch receivęs an equal amount of salt or sand. The student
measures the volume of ice remaining and subtracts it from the original volume of ice to see how
much melted away. What is a control variable in this experiment?
A. The size of the ice patches.
B. The type of salt applied to the ice.
C. The amount of ice that melted.
D. None of these.
Answer:
A. The size of the ice patches
Explanation:
In an experiment, the control variable also known as the CONSTANT is the variable that must be kept uniform or the same for all groups throughout the experiment in order not to influence the outcome of the experiment.
According to the experiment described in this question, the effect of different salts on melting points is investigated by a student. Sodium chloride (NaCl), Calcium Chloride (CaCl2), Potassium Carbonate (KCO3) and inert sand are the four types of salt used. The volume of the ice used and melted was finally measured. This means that the SIZE OF THE ICE PATCHES USED is the control variable of the experiment as the same size was used for all groups throughout.
Answer:
the size of the ice patches
Explanation:
in a chemical equation, where do the products appear
Answer:
products would appear after the raw materials
Explanation:
raw material + raw material = product (anything deriving from combining two materials)
Why does An apple, potato, and onion all taste the same if you eat them with your nose plugged
a body is moving along a circular path 'r'. what will be the distance and displacement of the body when it completed half a revolution?
After half of a revolution ...
==> Distance = π•r
==> Displacement = 2•r
a current of 6.0A runs through a circuit for 2.5 minutes how much change was delivered to this circuit
Answer:
900C
Explanation:
Change 2.5 mins to secs by multiplying by 60 which is 150secs
hope this helps please like and mark as brainliest
As a main sequence star exhausts hydrogen in its core, its surface becomes ___ and its energy output per second (luminosity) becomes ____.
Answer:
b
Explanation:
bc
Naomi Osaka, a Japanese-African-American tennis player is the 2021 Australian Open Champion, and the first Asian tennis player in Women's Tennis Association (WTA) history to be ranked first in Singles. To celebrate her win, Naomi Osaka hits a ball into the stands at 40. m/s and at an angle 30.° above the horizontal. On its way down, the ball is caught by a spectator 12 m above the point where the ball was hit.
a) Calculate the time it takes the tennis ball to reach the spectator.
b) Calculate the ball's horizontal range (horizontal distance travelled).
Answer:
(a) t = 0.75 s
(b) d = 26 m
Explanation:
Height, h = 12 m
Angle, A = 30 degree
initial velocity, u = 40 m/s
(a) Let the time is t.
Use second equation of motion
[tex]h = u t + 0.5 at^2\\\\12 = 40 sin 30 t - 0.5 \times10 \times t^2\\\\12 = 20 t - 5 t^2\\\\5 t^2 - 20 t + 12 =0 \\\\t = \frac{20\pm \sqrt{400-240}}{10}\\\\t = \frac{20\pm 12.65}{10}\\\\t = 3.3 s, 0.75 s[/tex]
(b) d = u cos A t
d = 40 x cos 30 x 0.75 = 26 m
Which diagram shows the most likely effect when a rock is weathered by water flowing over its entire surface
Answer:
the answer to this would be D.
Answer: Its D but it might swap to another letter so keep your eye out bud pass this test good luck
Explanation:
Help me and I'll make u Brainliest and follow u
26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
The moon's mass is____
a 1.18 x 1011 kg
b 7.35 x 1022 kg
С 5.32 x 10kg
d 3.20 x 1018 kg
Answer:
7.35kg
Explanation:
Hope this is helpful :)
What does the sun use for nuclear fusion?
Answer:
The sun uses hydrogen for nuclear fusion.
Answer:
Hydrogen
Explanation:
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26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
Which of the following is defined as a force that pushes and pulls the current through the circuit? Group of answer choices D) resistance B) electricity A) current C) voltage
Answer:
C voltage
Explanation:
Voltage is the change in electric potential so basically current flows from high potential to low potential due to voltage.
IA body starts to move from rest and travels with uniform acceleration of 7mls2. How far will the body move in 4 second .
why is fundamental unit called derived unit ?
Since fundamental units are elementary in nature and cannot be reduced further, so it can not be reduced further, so it cannot be expressed in other units
if the volume of cylinder is 1000 cm with 14cm height. Then find the radius of cylinder
Answer:
radius=4.77cm
Explanation:
given
r=? ,h=14 , v=1000
then using the formula
[tex]r = \sqrt{ \frac{v}{\pi \: h} } [/tex]
= √1000/π•14
=4.77cm
12. Which of these is more dense?
A. 10kg of a block of wood
B. 1kg of a block of styrofoam
C. 1kg of feathers
D. 10kg of feathers
E. 10kg of stryfoam
F. 1 kg of wood
Answer:
answer is E
Explanation:
20 swings takes 5 seconds in the pendulum. calculate the periodic time of the swing
Answer:
0.25s
Explanation:
5/20 = 0.25s
This might be correct
An ice skater pushes harder with her legs and begins to move faster. Which two laws best describes this
Answer:
Newton' second law and third law describes the situation.
Explanation:
According to the Newton's second law, the force applied on a body is proportional to the rate of change of momentum of the body.
According to the Newton's third law, for every action there is an equal and opposite reaction.
When ice skater pushes harder means more force is applied so he moves fast and more be the action force more be the reaction force.
Thus, Newton' second law and third law describes the situation.
what is the relationship between Hectare and cubic meter
If the radius of curvature of a mirror is 15m and the distance of the object from the mirror is 10m. Find the distance of the image from the mirror and the magnification of the object in meter
Answer:
Data given.
focal length (f)=15m÷2=7.5m
Distance of the object(U)=10m
Image distance (v)=?
Magnification (M)=?
Solution:
From:
1/f=1/u+1/v
1/7.5=1/10+1/v=75
then v=75m
Magnification, M=u/v
=75/10=7.5
Then magnification=7.5
Answer:
v = 30 m and m = 3
Explanation:
Given that,
The radius of curvature of the mirror, R = 15 m
Focal length, f = 7.5 m
Object distance, u = -10 m
We need to find the image distance and the magnification of the object.
Using mirror's formula,
[tex]\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}\\\\\dfrac{1}{v}=\dfrac{1}{f}+\dfrac{1}{u}\\\\\dfrac{1}{v}=\dfrac{1}{(7.5)}+\dfrac{1}{(-10)}\\\\v=30\ m[/tex]
The magnification of the object in mirror is given by :
[tex]m=\dfrac{-v}{u}\\\\m=\dfrac{-30}{-10}\\\\m=3[/tex]
So, the distance of the image from the mirror and the magnification of the object are 30 m and 3 respectively.
Quickly pls!!! A wave with a wavelength of 0.5 m moves with a speed of 1.5 m/s. What is the frequency of the wave?
A. 2.0 Hz
B. 1.0 Hz
C. 0.33 Hz
D. 3.0 Hz
Calculate the electric field acting on the electron in a hydrogen atom due to the proton in the nucleus the radius of the orbit of the electron is 5.3×10^-11
Answer:
[tex]F=-8.2*10^{-8}N[/tex]
Explanation:
From the question we are told that:
Radius [tex]r=5.3*10^{-11}[/tex]
Where
Proton Charge [tex]q_1=1.6*10^{-19}C[/tex]
Charge of Electron [tex]q_2=-1.6*10^{-19}C[/tex]
Generally the equation for Coulomb's Law is mathematically given by
[tex]F=\frac{9*10^9(q_1)(q_2)}{r^2}[/tex]
[tex]F=\frac{9*10^9(1.6*10^{-19}C)(-1.6*10^{-19}C)}{5.3*10^{-11}}[/tex]
[tex]F=-8.2*10^{-8}N[/tex]
If a wire lies withina magnetic field what must be true for the magnetic field to produce an electric current in the wire
Answer:
The magnetic field through the wire must be changing
Explanation:
According to Faraday's law, the induced emf, ε in a metallic conductor is directly proportional to the rate of change of magnetic flux,Φ through it. This is stated mathematically as ε = dΦ/dt.
Now for the wire, the magnetic flux through it is given by Φ = ABcosθ where A = cross-sectional area of wire, B = magnetic field and θ = angle between A and B.
So, dΦ/dt = dABcosθ/dt
Since A and B are constant,
dΦ/dt = ABdcosθ/dt = -(dθ/dt)ABsinθ
Since dθ/dt implies a change in the angle between A and B, since A is constant, it implies that B must be rotating.
So, for an electric current (or voltage) to be produced in the wire, the magnetic field must be rotating or changing.
what force to be required to accelerate a car of mass 120 kg from 5 m/s to 25m/s in 2s
Answer:
[tex]f = m \frac{v1 - v2}{t} \\ = 120 \times \frac{25 - 5}{2} \\ = 120 \times \frac{20}{2} \\ = 120 \times 10 \\ = 1200N \\ thank \: you[/tex]
Un auto que acelera a razón de 2 m/S^2 ; Si para cierto tramo se observa que logra triplicar su rapidez en 6 s. ¿Cuál fue su rapidez al final de estos 6 segundos?
Answer:
12m/s
Explanation:
Using the equation of motion
v = u + at
Given that
u = 0m/s
a = 2m/s²
time t = 6s
Substitute the given values into the expression
v = 0 + 2(6)
v = 0+12
v = 12m/s
Hence the required velocity is 12m/s
Se lanza una pelota de béisbol desde la azotea de un edificio de 25 m de altura con velocidad inicial de magnitud 10 m/s y dirigida con un ángulo de 63.1° sobre la horizontal. A) ¿Qué rapidez tiene la pelota justo antes de tocar el suelo? Use métodos de energía y desprecie la resistencia del aire.
Answer:
v_f = 24.3 m / s
Explanation:
A) In this exercise there is no friction so energy is conserved.
Starting point. On the roof of the building
Em₀ = K + U = ½ m v₀² + m g y₀
Final point. On the floor
Em_f = K = ½ m v_f²
Emo = Em_g
½ m v₀² + m g y₀ = ½ m v_f²
v_f² = v₀² + 2 g y₀
let's calculate
v_f = √(10² + 2 9.8 25)
v_f = 24.3 m / s