Answer:
t = 125 seconds
Explanation:
Given that,
The mass of a train, m = 50,000 kg
Initial speed, u = 5 m/s
Stopping force, F = 2000 N
We know that,
Force, F = ma
Where
a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{50000(0-5)}{-2000}\\\\t=125\ s[/tex]
So, it will take 125 seconds to stop the car.
a.
[tex]x + y = 0 \\ y = {x}^{2} + 2xy[/tex]
can any one tell this answer with dafination and all steps
Answer:
The system has two solutions:
(1, -1) and (0, 0)
Explanation:
We have the system of equations:
x + y = 0
x = x^2 + 2*x*y
To solve this, the first step is to isolate one of the variables in one of the equations, I will isolate x on the first one.
x = -y
Now we can replace this on the other equation, to get:
x = x^2 + 2*x*y
(-y) = (-y)^2 + 2*(-y)*y
Now we can solve this equation for y.
-y = y^2 - 2*y^2
-y = -y^2
y^2 - y = 0
We can solve this using the Bhaskara's formula:
The solutions are then:
[tex]y = \frac{-(-1) \pm \sqrt{(-1)^2 - 4*1*0} }{2*1} = \frac{1 \pm 1}{2}[/tex]
Then the two possible solutions are:
y = (1 + 1)/2 = 1
and
y = (1 - 1)/2 = 0
Suppose that we take the first one, y = 1.
Then the solution for x is given by "x = -y"
Then:
x = -1
This means that one solution of the system is (-1, 1)
If we take the other solution for y, y = 0
The value of x will be:
x = -y = -0 = 0
Then another solution of the system is (0, 0)
A schoolbus accelerates to 65 mph and enters the freeway. It travels for 2.3 hours at that speed while on the freeway. What's the distance travelled on the freeway?
Answer:
The distance travelled on the freeway is 149.5 miles.
Explanation:
The school bus travels on the freeway at constant speed. According to the statement, we need to calculate the distance travelled by the vehicle by means of the following formula:
[tex]x = v\cdot t[/tex] (1)
Where:
[tex]x[/tex] - Traveled distance, in miles.
[tex]v[/tex] - Speed, in miles per hour.
[tex]t[/tex] - Time, in hours.
If we know that [tex]v = 65\,\frac{mi}{h}[/tex] and [tex]t = 2.3\,h[/tex], then the distance travelled by the school bus is:
[tex]x = v\cdot t[/tex]
[tex]x = \left(65\,\frac{mi}{h} \right)\cdot (2.3\,h)[/tex]
[tex]x = 149.5\,mi[/tex]
The distance travelled on the freeway is 149.5 miles.
mercury is the closest planet to the sun, but its mean temperature is only 67°C. why is this?
Explanation:
Mercury is the closest planet to the sum, but its mean temperature is only 67°C. This is because Mercury has almost no atmosphere to hold in heat and keep the surface warm.
Hope it will help :)❤
When plane waves cross a boundary at a non-zero angle to the boundary, each wavefront experiences a change in ........... and ............ .
Answer:
When plane waves cross a boundary at a non-zero angle to the boundary, each wavefront experiences a change in direction and wavelength
Explanation:
Waves that cross the boundary from one medium to another, that have different densities at an angle to the boundary between the two medium is refracted (bent) in the second medium and experiences a change in direction and speed due to a change in the wavelength of the wave
How is an equation described if the number of atoms of each element in the products equals the number of atoms of each element in the reactants? a.not spontaneous b.balanced c.an acid-base reaction d.spontaneous
Answer: balanced
Explanation: i just took the test! :) hope this helps
In an equation, the number of atoms in products is equal to the number of atoms in reactant represents a balanced equation. Hence, option B is correct.
What are chemical reactions?It is a process in which one or more substance is converted into the other substances, is called chemical reactions. The chemical equation is given as A + B = C + D. A, B are reactants and C, D are products.
There are several types of chemical reactions like balanced reactions, spontaneous reactions, combination reactions and decomposition reactions.
Spontaneous reaction is a chemical reaction, in which the reactant is converted into product without the supply of external energy. The spontaneous reaction exothermic. The example for spontaneous reaction is combustion reaction.
Non-spontaneous reactions is a type of chemical reaction, in which the reactants can not be converted into product by its own. This reaction requires a external energy to undergo the chemical reaction. Electrolysis of water is an example of non-spontaneous reactions.
When there is exchange of one or more hydrogen ions (H⁺) between the reactant and product molecules is called acid-base reactions. This thpe of reaction is called as neutralisation reactions.
Balanced reactions is defined as the number of atoms in reactant is equal to the number of atoms in products. It is also said to be that when there is no inequalities between reactant and product.
Hence, if number of atoms in both reactant and product is equal, then it is called Balanced reactions. Thus, the correct option is B.
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On your first trip to Planet X you happen to take along a 100 g mass, a 40-cm-long spring, a meter stick, and a stopwatch. You're curious about the free-fall acceleration on Planet X, where ordinary tasks seem easier than on earth, but you can't find this information in your Visitor's Guide. One night you suspend the spring from the ceiling in your room and hang the mass from it. You find that the mass stretches the spring by 22.6 cm . You then pull the mass down 10.9 cm and release it. With the stopwatch you find that 10 oscillations take 18.8 s .
Answer:
[tex]g=2.513m/s^2[/tex]
Explanation:
From the question we are told that:
Mass Taken [tex]m=100g \approx 100*10^{-3}[/tex]
Strain on Spring [tex]l_s=22.6cm \approx 22.6*10^{2}[/tex]
Distance pulled down [tex]d_d=10.9[/tex]
Time for ten oscillations take [tex]t=18.8s[/tex]
Generally the equation for angular velocity is mathematically given by
[tex]\omega=2\pi\\\omega=2\pi*\frac{10\ oscillations}{t}\\\\\omega=2\pif=2\pi*\frac{10\ oscillations}{18.8}\\Also\\\omega=\sqrt{\frac{k}{m}} \\\omega=\sqrt{\frac{k}{100*10^{-3}}}[/tex]
Therefore
[tex]{2\pi*\frac{10\ oscillations}{18.8}}=\sqrt{\frac{k}{100*10^{-3}}} \\k=\sqrt{2\pi*\frac{10\ oscillations}{18.8}}*100*10^{-3}\\k=1.112N/m[/tex]
Generally the equation for Acceleration due to gravity is mathematically given by
[tex]F=mg\\mg=k l_s\\g=\frac{k l_s}{m}\\g=\frac{1.112*2.6*10^{2}}{100*10^{-3}}[/tex]
[tex]g=2.513m/s^2[/tex]
What is the total resistance of the circuit shown below?
Two-resistor parallel circuit
A. 50 ohms
B. 30 ohms
C. 25 ohms
D. 12 ohms
HELP
Answer:
D. 12Explanation:
I just did the Gizmo and the correct answer is 12 :) Hope this helps!
The total resistance of the circuit for parallel resistors of 41 Ω and 17 Ω is 12Ω. Hence option D is correct.
What is a parallel and series combination of resistance?When two or more resistors are connected between two same points, they are said to be connected in parallel combination(as shown in fig). The equivalent resistance is the reciprocal and the sum of reciprocals of all resistance connected in parallel combination.
[tex]\frac{1}{R_{s}} = \frac{1}{R_{1}} + \frac{1}{R_{2} } + \frac{1}{R_{3}} ..........+ \frac{1}{R_{n} }[/tex] where Rs is the equivalent or total resistance of the circuit.
In parallel combination, same potential difference exists across each resistor. But current through each resistance is different.
When two or more resistors are connected one after other, they are said to be connected in series as shown in figure. in this combination voltage difference across each resistance is different which is given by ohms law. current flowing through each resistance is same.
equivalent resistance for series combination is given by,
R(s) = R₁ + R₂ + R₃...........+R(n).
In this problem given resistance are not seen, Resistor can be with 41 and 17Ω.
Given,
R₁ = 17 Ω
R₂ = 41 Ω
[tex]R_{s} = ?[/tex]
by parallel combination,
[tex]\frac{1}{R_{s}} = \frac{1}{R_{1} } + \frac{1}{R_{2} }[/tex]
[tex]R_{s} = \frac{R_{1} R_{2} }{R_{1} + R_{2} }= \frac{17*41}{17+41} = \frac{697}{58} = 12[/tex]
R = 12 Ω.
Hence option D is correct.
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What effect would constriction of the blood vessels have on the body?
Answer:
When blood vessels constrict, the flow of blood is restricted or decreased, thus retaining body heat or increasing vascular resistance. this makes the skin turn paler because the blood reaches the surface, reducing the radiation of heat. hope this helps
Which would result in an increase in the magnetic field strength produced by an electromagnet? A) increasing the space between the turns in the coil B) increasing the number of turns in the coil C) decreasing the current in the coil D) decreasing the voltage in the coil
Answer:
B) increasing the number of turns in the
Explanation:
A) Increasing the space between the turns in the coil will decrease the number of coils. It will result in a decrease in the strength of the magnetic field because the strength of the magnetic field of an electromagnet is directly proportional to the number of coils.
B) Increasing the no. of turns in the coil will result in an increase in the strength of the magnetic field.
C) Strength of magnetic field is directly proportional to the magnitude of current passing through the electromagnet. Therefore, decreasing the current will decrease the strength of the magnetic field.
D) Decreasing the voltage will decrease the current and as a result, the strength of the magnetic field will also be decreased.
Hence, the correct option is:
B) increasing the number of turns in the
Which statement is correct about waves?
A. All waves move at the same speed in any
medium.
B. Waves carry the energy but do not carry the matter.
C. Waves must always move from one place to another.
D. Sound waves have more energy than light waves.
Answer:
b is the correct answer
Explanation:
Erosion and Weathering can cause changes in earths surface but how does erosion alone changes the earth surface.
Answer:
The action of erosion alone can change the earth's surface. Erosion can wash away nutrients on the earth's surface, change the appearance of the soil of a particular area over time, can bore holes, that form caves, change landscapes for example when the earth is hit with gully erosion by continuous water runoff over time. Erosion can move soil to a new area.
Explanation:
Weathering involves breaking down rock into smaller pieces without any form of formal movement of those broken rock pieces. These processes that can lead to weathering are caused by mechanical, chemical, and organic processes which can happen over time. Erosion can now move broken rock pieces or soil to another place by water or wind. Weathering and erosion constantly change the Earth's surface.
The periodic wave in the diagram below has a frequency of 80. hertz.
What is the speed of the wave? (1) 13 m/s (2) 60. m/s (3) 27 m/s (4) 120 m/s
Answer:
hi how are you
2) 5/8
4) 5/8
A piece of stone weigh 90 grams. When it lowered in measuring cylinder containing water. The final volume of water is 30 cubic centimetres. Calculate the density of the stone.
Answer:
3 gm / cm^3
Explanation:
Density = weight / volume
90 / 30 = 3 gm/cm^3
A 0.7 tennis ball is thrown with a velocity of 20 m second to the right what is the momentum of the tennis ball
Explanation:
Momentum of an object is defined as the product of the mass of object and the velocity with which it is moving.
p = mv
where, p = momentum, m= mass and v= velocity
mass m = 0.7 Kg and v = 20 m/s
p = 0.7×20 = 14 Kg-m/sec
Therefore, momentum of the object = 14 kg-m
Describe the net transfer of thermal energy and any changes in temperature When a metal block at 300Ak is placed in water at 15°C
Answer:
Q_c = Q_abs
Explanation:
You are asked to describe the process when placing a hot block in cold water.
The first thing to do is put all the quantities in the same units
block temperature T_bloque = T_h = 300 K = 300 -273 = 27ºC
water temperature T_water = T_c = 15ºC
* initially the block cools down decreasing its temperature
* the water temperature increases
* the equilibrium is established when the thermal energy of the two bodies is equal, therefore they have the same temperatures T_f
* Conservation of energy requires that the energy released by the hot block is equal to the energy absorbed by the cold body (water)
transferred thermal energy Q_c = m_block ce_block (T_h-T_f)
absorbed thermal energy Q_abs = m_agua ce_agua (T_f - T_c)
* if we subtract the energy transferred and the absorbed gives zero, therefore the net energy transferred is zero
Q_c = Q_abs
what is a car doing as it rounds a curve
Answer:
its direction is changing
List out of how animals and plants can cause weathering.
Plants
2. A block of mass 1.2 kg lies on a frictionless surface. A man slides the block
against a spring, compressing it .15m. When the man lets go of the spring, the
block moves at 5 m/s. What is the spring constant of the spring?
mm
.
Answer:
The spring constant will be "1333.33 N/m".
Explanation:
The given values are:
Mass,
m = 1.2 kg
Displacement compression,
x = 0.15 m
Block's velocity,
[tex]v_i=5 \ m/s[/tex]
As we know,
⇒ [tex]E_i=E_f[/tex]
or,
⇒ [tex]K_i+v_i=K_f+v_f[/tex]
⇒ [tex]\frac{1}{2}mv_i^2+0=0+ \frac{1}{2}Kx^2[/tex]
So,
⇒ [tex]K=\frac{mv_i^2}{x_2}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{1.2\times 5\times 5}{0.15\times 0.15}[/tex]
⇒ [tex]=\frac{30}{0.0225}[/tex]
⇒ [tex]=1333.33 \ N/m[/tex]
Which statement describes an interacting force pair represented by the third law of motion? The force exerted by a cyclist equals the combined forces of friction and air resistance. A car exerts a force on a bug as they collide and the bug exerts an equal force on the car. Gravity exerts a downward force on a refrigerator and the normal force pushes up on the refrigerator. Two people pull on opposite ends of a rope, but the rope does not move because the people pull with equal forces.
Answer:
A car exerts a force on a bug as they collide and the bug exerts an equal force on the car.
Explanation:
Newton's third law of motion states that for every action there is an equal and opposite reaction.
Action-reaction force pairs make it possible for fishes to swim, birds to fly, cars to move etc,
Furthermore, take for example, While driving down the road, a firefly strikes the windshield of a car (Action) and makes a quite obvious mess in front of the face of the driver (Reaction) i.e The firefly hit the car and the car hits the firefly.
Hence, the statement which best describes an interacting force pair represented by the third law of motion is, a car exerts a force on a bug as they collide and the bug exerts an equal force on the car.
The ultimately implies that, in every interaction, there is a pair of forces acting on the two interacting objects in this case, the car and bug. The size of the force on the car equals the size of the force on the bug. These two forces are called action and reaction forces and are the subject of Newton's third law of motion.
why was Idi Amin labeled as one of the Africa's cruelest dictators
Answer: He was labeled as one of Africa's cruelest dictators because during his eight year reign many civilians were massacred. He drove out Uganda's Indian and Pakistani citizens and spent large amount of money on the military which led to the economic decline of the country.
Explanation:
Several merchant ships reports rogue waves
which are estimated to be 25 meters high and 26 meters long. Assuming that these waves travel at
speeds of 6.5 m/s, determine the frequency and the period of these waves.
Answer:
The frequency is 0.25Hz and the period is 4s
Explanation:
To solve this we can use the formula: [tex]f = \frac{v}{\lambda}[/tex], where f=frequency, v=velocity and lambda = wavelength.
In the question, we are given the information that the velocity of the wave is 6.5m/s and the wavelength is 26 meters long. By putting these values into the formula, we can find the frequency:
[tex]f=\frac{6.5}{26} \\f= 0.25Hz[/tex]
Period is the inverse of frequency: [tex]T=\frac{1}{f}[/tex]
Therefore the period is: [tex]T = \frac{1}{0.25} \\T = 4s[/tex]
Hope this helped!
2. Before 0.5-kg ball is dropped from a third story window 20 m above the sidewalk. What is the potential
energy of the ball?
a. 4 J
b. 9800 J
C. 98 J
d. 150 J
Answer:
C
Explanation:
C
20*9.8*0.5
98
Testing shows that a sample of wood from an artifact contains 12.5% of the original amount of carbon-14. Given that the half-life of carbon-14 is 5730 years, how old is the artifact?
A. 22,920 years
B. 17,190 years
C. 11,460 years
D. 5730 years
Answer:
B. 17,190
Explanation:
got it right, trust
The age of the artifact is 17190 years. So, the correct option is B.
What is meant by half life ?The amount of time needed for half of a radioactive sample's atomic nuclei to spontaneously decay (transform into another nuclear species by producing particles and energy) is known as the half-life.
Here,
Amount of Carbon-14 present in the given sample = 12.5 %
Given that the half-life of Carbon-14 is 5730 years. That means after a period of 5730 years, the percentage of Carbon-14 present in the sample will be 50% of the original amount.
So, age of the artifact when 50% is present is 5730 years.
Thus, after a period of 2 half-lives, the amount of carbon-14 present will be, 25%.
So, age of the artifact when 25% is present,
t = 2 x 5730 = 11460 years
Therefore, we can say that,
The age of the artifact when 12.5% is present,
t' = 3 x 5730 = 17190 years
Hence,
The age of the artifact is 17190 years. So, the correct option is B.
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A string is being driven by a motor with a frequency of 10 Hz. If the speed of the waves travelling down the string is equal to 24 m/s, what is the wavelength?
Answer:
λ = 2.4 m
Explanation:
The speed of a wave is defined as the product of the frequency and the wavelength of that wave:
[tex]v = f\lambda[/tex]
where,
v = speed of wave = 24 m/s
f = frequency of wave = 10 Hz
λ = wavelength of the wave = ?
Therefore,
[tex]24\ m/s = (10\ Hz)\lambda\\\\\lambda = \frac{24\ m/s}{10\ Hz}[/tex]
λ = 2.4 m
Doing science by inquiry always involves:
Answer asap! No links or weird answers pls. Thank you
An object with a mass of 5.4 kg has a force of 20.0 Newton’s applied to it. What is the resulting acceleration?
Answer:
Mass (m) = 5.4 kg
Force (f) = 20 N
Acceleration (a) = ?
Acceleration= m × a
[tex]m \times a \\ = 5.4 \times 20 \\ = 108 \: ms ^{ - 2} [/tex]
=> The resulting acceleration of the object is 108 m/s².
Horticulture 120 pts (HURRY)
Auto-steer technology is dependent on the use of
tracking relayed from satellites to receivers and transmitters in the farm equipment.
Answer: GPS
Explanation:
I took the test 2021
Answer:
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Haile's plane travels forward for a few feet and then begins to fall. What would explain the plane's ability to travel forward for a few feet without falling?
Answer:
Aircraft never crash because of one single issue. It's almost always a combination of factors that lead to an accident. Whilst flying is extremely safe, typical reasons why planes crash include pilot error, technical failures, bad weather, terrorism, and pilot fatigue.
Answer The force of the air pushing up on the plane is
equal to the force of gravity pulling down on the
plane.
A chart showing the type of reproduction that occurs in several organisms is shown below. Organism Type of Reproduction Bacteria Asexual Salmon Sexual Oak Trees Both Bears Sexual Asexual Flatworms Based on the information on the chart, which organisms are able to produce genetically diverse offspring? A Bacteria, oak trees, and flatworms B Salmon, oak trees, and bears C Salmon and bears only D Bacteria and flatworms only
Answer:
C
Explanation:
Answer:
B
Explanation:
Because it’s asking about sexual
Which is NOT something that all green plants have in common?
1.They make their own food.
2. They reproduce.
3 .They grow.
4 .They produce flowers.
Answer:
4
Explanation:
Not all plants can grow flowers. Only the ones thay have buds can.
Not all plants produce flowers. Hence, this is the characteristic which is not common in all plants.Therefore, the correct option is 4.
What are flowers?Flowers are the structures of plants. They are responsible for producing seeds that will grow into new plants. Flowers typically consist of a colorful or ornamental part called the corolla, which attracts pollinators such as bees and butterflies, and a reproductive part called the stamen and pistil, which contain the plant's male and female organs.
Not all green plants produce flowers. Flowering plants are a type of plant that belong to the group Angiosperms, but there are also non-flowering plants like ferns and mosses that do not produce flowers. Therefore, the correct option is 4.
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