Given :
A 12,500 kg railroad freight car travels on a level track at a speed of 5.2 m/s.
It collides and couples with a 22,600 kg second car, initially at rest and with brakes released.
To Find :
The speed of the two cars after collision.
Solution :
It is given that car couples with each other. So speed of both the cars after collision is same. Let, it be v.
Applying conservation of momentum, we get :
[tex]m_1u_1 + m_2u_2 = (m_1 + m_2 )v\\\\12500\times 5.2 + 22600\times 0 = ( 35100)v\\\\35100v = 65000\\\\v = 1.85\ m/s[/tex]
Therefore, the speed of the two cars after collision is 1.85 m/s.
What are the magnitude and direction of electric field at the center of square?
Answer:
hello the diagram related to this question is missing attached below is the missing diagram
Answer :
The magnitude of the electric field = 4KQ / L^2
direction = 45° east to south
Explanation:
The magnitude of the electric field = 4KQ / L^2
direction = 45° east to south
A branch falls from a tree How fast is the branch moving after 0 28 seconds
A. 44 m/s
3.3.1 m/s
c. 2.7m/
D. 13 m/s
Answer:
c. 2.7 m/s
Explanation:
[tex]v = a.t + v_{0}\\a = g = 9.81 m/s^{2}} \\t=0.28 s \\v_{0} = 0\\=> v = 9.81 * 0.28 = 2.74 m/s[/tex]
6. What are formed from the chemical reaction of the substances given
below? Write the balanced chemical reaction as well.
a) When carbon burns in air
b) When calcium carbonate is heated
c) When a piece of burning magnesium ribbon is inserted in the
jar filled with oxygen gas.
d) When hydrogen peroxide gets dissociated in the presence of
manganese dioxide.
e) When
chemical reaction between calcium carbonate
and hydrochloric acid takes place.
Answer:
1) CO2
2) CO2 and CaO
3) MgO
4) H20 and O2
5) CaCl2, CO2, H2O
Explanation:
Now let us try to put down the reactions here;
1) C(s) + O2(g) -------> CO2(g)
2) CaCO3(s) -------> CaO(s) + CO2 (g)
3) 2Mg(s) + O2(g)------> 2MgO
4) 2H2O2(aq) --------> 2H2O(l) + O2(g)
5) CaCO3(s) + 2HCl(aq) ------> CaCl2(aq) + CO2(g) + H2O(l)
Note that a chemical reaction equation is only said to be balanced when the number of atoms of each element on both sides of the reaction equation are exactly the same.
A 1.0 kg mass at the end of a spring has an amplitude of 0.10 m and vibrates 2.0 times per second. What is its velocity when it is 0.10 m from equilibrium.
Answer:
[tex]v=0m/s[/tex]
Explanation:
From the question we are told that
Mass of object[tex]M=10kg[/tex]
Amplitude[tex]A=0.10m[/tex]
SHM [tex]w=2.0 times per second.[/tex]
Distance from equilibrium [tex]0.10m[/tex]
Generally the equation for SHM displacement from equilibrium position is mathematically given by
[tex]v=Aw\sqrt{1-\frac{x^2}{A^2}}[/tex]
For [tex]x=0.10[/tex]
Therefore
[tex]v=Aw\sqrt{1-\frac{0.10^2}{A^2}}[/tex]
[tex]v=0.10*2\sqrt{1-\frac{0.10^2}{0.10^2}}[/tex]
[tex]v=0.10*2\sqrt{1-1}[/tex]
[tex]v=0m/s[/tex]
A water tank is filled with water up to 3.5m in height. calculate the pressure given by the tank at its bottom.
Answer:
Explanation:
We are told that the height of the water tank is 3.5 m.
Now, the formula for pressure is;
P = ρgh
Where;
ρ is density of water = 1000 kg/m³
g is acceleration due to gravity = 9.8 m/s²
h = 3.5 m
Thus;
P = 1000 × 9.8 × 3.5
P = 34300 N/m²
Which pair of waves could overlap to produce a wave with a higher amplitude
through interference?
A. Two waves of the same amplitude with crests that overlap troughs
B. Two waves of the same amplitude with crests that are perfectly
aligned
C. Two waves of different amplitudes that are also different types of
waves
D. Two waves of different amplitudes with crests that overlap
troughs
Answer: The Answer is B (Sorry if this is late)
Explanation:
I couldn’t find the answer to the question myself then found you, with no answer. So I guessed and failed my third question of the quiz, you were worth the sacrifice though ✨
The pair of waves could overlap to produce a wave with a higher amplitude through interference is that two waves of the same amplitude with crests that are perfectly aligned. Hence, option B is correct.
What is Amplitude?The maximum deflection or distance made by a point on even a vibrating object or wave relative to its equilibrium location is known as the amplitude in physics. It is equivalent to the length of a vibration path divided in half.
A pendulum's amplitude is therefore equal to the distance that the bob travels when swinging through one side to another. Vibrating sources produce waves, whose amplitude is inversely proportional to the source's amplitude.
The largest deviation of any place on the string out of its place when the line is at rest is used to determine the amplitude of a wave propagation, like the wave on such a plucked string.
Therefore, it concludes that option B is correct.
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100 point question!! A driver begins to brake when her car is traveling at 15.0 m/s, and the car comes to a stop 4.0 s later. How much farther does the car go after the driver begins to brake, assuming constant acceleration?
Answer:
30 m
Explanation:
Let's list out the known variables that we are given in this question.
v₀ = 15 m/sv = 0 m/s t = 4 sWe are trying to solve for displacement in the x-direction.
Δx = ?Find which constant acceleration equation contains all 4 of these variables.
[tex]\displaystyle \triangle x = \Big (\frac{v+v_0}{2} \Big ) t[/tex]Plug the known values into the equation and solve for delta x.
[tex]\displaystyle \triangle x = \Big (\frac{0+15}{2} \Big ) \cdot 4[/tex] [tex]\displaystyle \triangle x = \Big (\frac{15}{2} \Big ) \cdot 4[/tex] [tex]\displaystyle \triangle x =\frac{60}{2}[/tex] [tex]\triangle x = 30[/tex]The car goes 30 m after the driver begins to brake.
Answer:
the answer should be 30 m
Explanation:
have a good day
A 1110 kg car moving at 21 m/s East is struck by a truck traveling West. The truck's impact exerts a force of -8000 kg•m/s2 for 0.90 seconds. Calculate the car's final velocity.
Answer:
v = 15.23 m/s
Explanation:
Given that,
Mass of a car, m = 1110 kg
Initial velocity, u = 21 m/s
Force,F = -8000 N
Time, t = 0.9 s
We need to find the final velocity of the car.
Force, F = ma
[tex]F=\dfrac{m(v-u)}{t}\\\\v-u=\dfrac{Ft}{m}\\\\v=\dfrac{Ft}{m}+u\\\\v=\dfrac{-8000\times 0.8}{1110}+21\\\\v=15.23\ m/s[/tex]
So, the final velocity of the car is 15.23 m/s.
The propeller of an aircraft is spinning at 10 rev/s when the pilot shuts off the engine. The propeller reduces its angular velocity at a constant 2.0rad/s2 for a time period of 40 s. What is the rotation rate of the propeller in 40 s
One revolution of the propeller corresponds to a rotation of 2π radians, so that the propeller has an initial angular velocity of
10 rev/s = (10 rev/s) • (2π rad/rev) = 20π rad/s
The propeller thus has an angular velocity ω at time t of
ω = 20π rad/s - (2.0 rad/s²) t
so that at t = 40 s, its angular speed is reduced to
20π rad/s - (2.0 rad/s²) (40 s) = (20π - 80) rad/s
Convert this to a rotation rate by dividing this result by 2π :
(20π - 80) rad/s = ((20π - 80) rad/s) • (1/(2π) rev/rad) ≈ -2.73 rev/s
which would suggest that the propeller has started to turn in the opposite direction at a rate of 2.73 rev/s.
The creation of electricity in a coil of a wire through the movement of a magnet is called what?
A) electromagnet
B) Magnetosphere
C) Magnetism
D) Electromagnetic Induction
Answer:
D. Electromagnetic Induction.
Explanation:
What determines the radiation that an electromagnetic wave emits?
a. its speed
b. its visibility
c. its amplitude
d. its wavelength
PLEASE HELP!!!!
The electromagnetic waves are determined by the wavelength. Hence, the correct option is D.
What are electromagnetic waves?Electromagnetic waves are made up of vibrating electric and magnetic fields. The electric and magnetic fields are mutually perpendicular to each other. EM waves are transverse in nature.
Electromagnetic waves can travel through the vacuum in the form of radiation. The EM waves travel with the speed of light 3×10⁸ m/s. EM waves have no mass and charge. These waves can carry energy in space.
The behavior of electromagnetic waves depends on its frequency and wavelength. EM waves are classified into 7 types based on its frequency and wavelength. They are classified from radio waves to Gamma rays.
Frequency is inversely proportional to wavelength, f = c / λ. Higher frequencies have shorter wavelength and lower frequencies have longer wavelength.
Thus, the wavelength determines the radiation that an electromagnetic waves. Hence, the option D is correct.
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14. The average speed of a car was 60 m/s by the time it reached the finish line. The car moved in a straight line and traveled from the starting
line to the finish line in 8.0 sec. How far was the finish line?
The highest point on the American eagle roller coaster is 39 meters above the ground. Find the potential energy of a 625 kg roller coaster car that is at its highest point on the track. Use g=10m/s
Answer:
243.75kJ
Explanation:
Step one:
Given parameters
Height= 39meters
mass= 625g
g= 10m/s
Required
The potential energy PE
Step two:
the expression for the potential energy is given as
PE=mgh
PE=625*10*39
PE=243750 J
PE=243.75kJ
A skateboarder starts at point A on the ramp and rises to point B, a maximum height of h = 3.01 m above the top of the ramp.If the amount of work done against friction is insignificant, determine his initial speed (in m/s) at point A
Answer:
7.68m/s
Explanation:
At point A, height h= 0m where v=?
At point B, height of h = 3.01 m above the top of the ramp v= 0 m/s
The conservation of energy here will be energy at Point A equals energy at point B
g= acceleration due to gravity= 9.81m/s^2
(mgh + 1/2 mv^2)A = (mgh + 1/2 mv^2)B
✓But height h at point A= 0 m then energy at point A= 1/2 mv^2
✓At point B , the velocity v= 0 m/s, then Energy at point B= mgh
✓ if we equate both energy at point A and B we have
mgh=1/2 mv^2
Let us make v the subject of formula, and cancel out the "m"
v=√2gh
Then substitute the values
V= √2×9.81×3.01
V=7.68m/s
Hence, his initial speed (in m/s) at point A is 7.68m/s
A pipe that is open at both ends has a fundamental frequency of 320 Hz when the speed of sound in air is 334 m/s. What is the length of this pipe
Answer:
Length of pipe 0.5m
Explanation:
Step one
Given data
fundamental frequency of 320 Hz
n=1
Velocity v=334m/s
Note: the subsequent frequency of sound are a multiple of it fundamental frequency
Step two
Applying the formula we have
Fn=nv/2l
Substitute
320=1*334/2L
Cross multiply
320*2L=334
640L=334
Divide both sides by 640
L=334/640
L=0.5m
What is a common cause of insomnia? (2 points)
Eustress
Type B personality
Chronic stress
Functional fixedness
Answer:
stress
Explanation:
Common causes of chronic insomnia include: Stress. Concerns about work, school, health, finances or family can keep your mind active at night, making it difficult to sleep. Stressful life events or trauma — such as the death or illness of a loved one, divorce, or a job loss — also may lead to insomnia.
Answer:
C. Chronic Stress
Explanation:
I took the test
How much gravitational force attracts a ball weighing 300 kilograms ?
Given that,
Mass of a ball = 300 kg
To find,
The gravitational force acting on the ball.
Solution,
The force acting on the ball is force of gravity. It is equal to the weight of the ball.
W = mg
Substitute the value of m and g in the above formula
W = 300 kg × 10 m/s²
= 3000 N
Therefore, the ball attracts with a force of 3000 N.
What are the characteristics of open pit mining
Answer:
The dominant feature in an open pit or quarry operation is the pit, a broad, deepened, often funnel-shaped area where overburden has been removed to access the material to be mined. This is where material extraction takes place.
Explanation:
Read my bio :)
According to the cell theory, which statement is correct? A) Viruses are true cells. B) Cells are basically unlike in structure. C) Mitochondria are found only in plant cells. D) Cells come from preexisting cells.
Answer:
D) Cells come from preexisting cells.
Explanation:
The universal i.e widely accepted cell theory was proposed in 1800's by the contribution of three scientists namely Theodor Schwann, Matthias Schleiden, and Rudolf Virchow. They came together and proposed three main components that make up the cell theory today. The components are:
- All living things are composed of one or more cells.
- Cell is the basic and fundamental unit of life
- All cells come from preexisting cells.
Based on these three components of the cell theory, the statement that: "Cells come from preexisting cells" in the options is correct.
what is the difference between a 4x100 and a 4x400 relay
A force of attraction would exist between
A.
a negatively charged object and a neutral object.
B.
two negatively charged objects.
C.
a positively charged object and a negatively charged object.
D.
two positively charged objects.
Answer:
D. two positively charged objects
FILL IN THE BLANK.
The __________ of a vector is represented by the length of the arrow.
Answer:
magnitude
Explanation:
because
The data table shows how the amplitude of a mechanical wave varies with
the energy it carries. Analyze the data to identify the mathematical
relationship between amplitude and energy. Use your equation to find the
energy if the amplitude is 9 units.
Amplitude
Energy
1 unit
2 units
2 units
8 units
3 units
18 units
4 units
32 units
Answer:
162 units
Explanation:
Just did it on A pex
The equation for the energy from the data table shows how the amplitude of a mechanical wave varies with the energy it carries is E = 2 × A², and the energy, if the amplitude is 9 units, is 36 units.
What is a wave?The disturbance oscillates periodically (see the periodic motion) with a set frequency and wavelength in the simplest waves. While electromagnetic waves (see electromagnetic radiation) do not require a medium to travel through and can move through a vacuum, mechanical waves, like sound, need one. The characteristics of the medium determine how well a wave travels through it.
Given:
The energies are, 2, 8, 18, 32
The amplitudes are, 1, 2, 3, 4
Calculate the energy at 9 of amplitude as shown below,
The general formula can be E = 2 × A²
Here, A is the amplitude, and energy is E,
Plug the value of the amplitude
Energy = 2 × 9²
Energy = 2 × 18
Energy = 36
Thus, the energy is 36.
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Can a light bulb work without energy transfer.
Answer:Energy cannot be created or destroyed. It can be stored, or it can be transferred i.e. from a hot object to a cool object by conduction, convection or radiation.
Explanation:
is cereal a soup? aCTUALLY EXPLAIN WHY OR WHY NOT!
Answer:
No
Explanation:
Cereal is cereal and soup is soup.
The only planet in the solar system with the temperature that can support life is
Answer:
earth
Explanation:
its the only planet.
Just 4 questions, I’ll give brainiest and pts the questions are in the photo
Answer:
1. Divide the weight by speed of the people pushing it to get net force
2. Whether one side of the object is pushing harder or not you will get ur answer, for example if the left side is pushing 3 newtons to the right and the right side pushing 5 newtons to the left, the net force would be 2 newtons of force pushing left and if its an even amount of force then it will be 0
3. If one side of an object pushes harder than the other side, then the object will move in favor of the one who is pushing harder.
4. 200 newtons or 200N
Explanation:
To open a soda can lid, a force of 50 N is applied to a car key, which acts as a lever. If the car key applies a force of 400 N to the lid, then the mechanical advantage of the car key is ___.
a 12
b 10
c 6
d 8
Explanation:
Given. Required
wo = 400N. MA=?
wi = 50N
Solution
MA = wo = 400N =8
wi. 50N
20 points please help!!
Write a hypothesis about the effect of temperature and surface area on the rate of chemical reactions using this format: “If . . . then . . . because. . . .” Be sure to answer the lesson question, “How do the factors of temperature and surface area affect the rate of chemical reactions?”
Answer:
Sample Response: If temperature and surface area increase, then the time it takes for sodium bicarbonate to completely dissolve will decrease, because increasing both factors increases the rate of a chemical reaction.
Explanation:
A batter hits a ball and it is caught 4 seconds later 100 m from home plate. What is the initial velocity (vector!!!) of the ball?(Note: the ball is hit and caught at the same distance from the ground.
Answer:
The initial velocity vector of the ball is;
[tex]\underset{u}{\rightarrow}[/tex] = 25·i + 19.6·j
Explanation:
The given parameters are;
The time of flight of the ball = 4 seconds
The horizontal distance from the plate at which the ball is caught = 100 m
Let 'u', represent the initial velocity, we have;
u × cos(θ) × t = u × cos(θ) × 4 s = 100 m
u × cos(θ) = 25 m/s...(1)
[tex]t = \dfrac{2 \cdot u \cdot sin(\theta)}{g} = \dfrac{2 \cdot u \cdot sin(\theta)}{9.8 \ m/s^2} = 4 \ seconds[/tex]
∴ 2·u·sin(θ) = 9.8 m/s² × 4 s = 39.2 m/s
[tex]\therefore \dfrac{2 \cdot u \cdot sin(\theta)}{u \cdot cos(\theta)} = 2 \cdot tan(\theta) = \dfrac{39.2 \ m/s}{25 \ m/s} = 1.568[/tex]
tan(θ) = 1.568/2 = 0.784
θ = arctan(0.784) ≈ 38.096°
The direction of the velocity vector of the ball, θ ≈ 38.096°
From equation (1), we have;
u × cos(θ) = 25 m/s
∴ u = 25 m/s/cos(θ) = 25 m/s/cos(arctan(0.784)) = 31.7672787629 m/s
The magnitude of the initial velocity vector, u = 31.7672787629 m/s
The vertical component of the initial velocity, [tex]u_y[/tex] = u × sin(θ)
∴ [tex]u_y[/tex] = 31.7672787629 × sin(arctan(0.784))
Therefore, the initial velocity vector of the ball is approximately, v = 31.767 m/s in a direction 38.096° above the horizontal, from which we have;
u = uₓ·i + [tex]u_y[/tex]·j = 25·i + 19.6·j
[tex]\underset{u}{\rightarrow}[/tex] = 25·i + 19.6·j