Answer:
7.89 m/s
Explanation:
Given that
Width of the river, b1 = 12 m
Width of the river, b2 = 5.8 m
Depth of the river, d1 = 2.7 m
Depth of the river, d2 = 0.85 m
Speed of the river, v1 = 1.2 m/s
Speed of the river, v2 = ?
Area of the river before the rapid, a1 = 12 * 2.7 = 32.4 m²
Area of the river after the rapid, a2 = 5.8 * 0.85 = 4.93 m²
To solve this question, we use a relation between the speed of the river and the volume of the river. We say,
Area1 * velocity1 = Area2 * velocity2, and when we substitute the values for each other we have
32.4 * 1.2 = 4.93 * v2
38.88 = 4.93v2
v2 = 38.88 / 4.93
v2 = 7.89 m/s
Therefore, the speed of the river after the rapid is 7.89 m/s
12. A 20-newton cart is lifted up 0.40 meters to the top of a ramp.
What is the amount of potential energy gained by the cart? A
Please show your work and I need it fassst
Answer:
8 joules
Explanation:
Just did it
Answer:
8 J
Explanation:
Potential energy = mass x gravitational field strength x height
Gravitational field strength is accelerations due to gravity which is 9.8m/s² ( you can round it up and take 10 as well)
Mass = Force ÷ Acceleration
20 ÷ 9.8 = 2.04
Potential energy = 2.04 x 9.8 x 0.40
= 7.99 = 8 J
Through which material would you expect sound waves to move fastest? O A. Iron O B. Water O c. Air O D. Milk
Answer:
Solids
Is this what your looking for, It might tell you the answer?
What is the force required to stretch a spring whose constant value is 35 N/m by an amount of 0.25 m?
Answer:
or whatever then look it up it
Explanation:
An observer stands 150 meters from a fireworks display rocket, which is fired directly upward. When the rocket reaches a height of 200 meters, it is traveling at a speed of 12 meters/second. At what rate is the angle of elevation formed with the observer increasing at that instant
Answer:
[tex]-0.288\ \text{rad/s}[/tex]
Explanation:
x = Distance of observer from the initial location of the rocket = 150 m
y = Vertical displacement of the rocket from the ground = 200 m
r = Distance between observer and rocket
[tex]\dfrac{dy}{dt}[/tex] = Rate of change in height of rocket = 12 m/s
[tex]\dfrac{dx}{dt}[/tex] = Rate of change in x = 0
Distance between observer and rocket at y = 200 m
[tex]r=\sqrt{x^2+y^2}\\\Rightarrow r=\sqrt{150^2+200^2}\\\Rightarrow r=250\ \text{m}[/tex]
[tex]\tan\theta=\dfrac{y}{x}[/tex]
Differentiating with respect to time
[tex]\sec^2\theta\dfrac{d\theta}{dt}=\dfrac{y\dfrac{dx}{dt}-x\dfrac{dy}{dt}}{x^2}\\\Rightarrow \dfrac{d\theta}{dt}=\dfrac{\dfrac{y\dfrac{dx}{dt}-x\dfrac{dy}{dt}}{x^2}}{\sec^2\theta}\\\Rightarrow \dfrac{d\theta}{dt}=\dfrac{\dfrac{0-150\times 12}{150^2}}{(\dfrac{250}{150})^2}\\\Rightarrow \dfrac{d\theta}{dt}=-0.288\ \text{rad/s}[/tex]
The rate of change of the angle of elevation is [tex]-0.288\ \text{rad/s}[/tex].
When the plutonium bomb was tested in New Mexico in 1945, approximately 1 gram of matter was converted into energy. Suppose another bomb is tested, and 1.5 grams of matter are converted into energy. How many joules of energy are released by the explosion?
Answer:
The value is [tex]E = 1.35 *10^{14} \ J[/tex]
Explanation:
From the question we are told that
The mass of matter converted to energy on first test is [tex]m = 1 \ g = 0.001 \ kg[/tex]
The mass of matter converted to energy on second test [tex]m_1 = 1.5 \ g = 1.5 *10^{-3} \ kg[/tex]
Generally the amount of energy that was released by the explosion is mathematically represented as
[tex]E = m * c^2[/tex]
=> [tex]E = 1.5 *10^{-3} * [ 3.0 *10^{8}]^2[/tex]
=> [tex]E = 1.35 *10^{14} \ J[/tex]
As the fragment falls through the atmosphere it is heated and some of the material is vaporized. Explain how you could determine the composition of this hot vaporized material from the light it emits.
Answer:
by determining the wavelength of the light emitted
Explanation:
The composition of the hot vaporized materials of an asteroid can be find out by the wavelength of the light emitted when the fragment material is burnt out.
Some of the asteroids that are very large do not burn completely in the atmosphere and they fall on the surface of the earth. Thus there is a possibility of radioactivity. An atom is radioactive or unstable when the forces that constitutes the nucleus are not balanced and then the nucleus have excess of energy. Thus these unstable and highly energetic nucleus will try to attain stability by ejecting protons and neutrons, or by releasing gamma rays, beta particles or positrons, etc. Thus they will radiate energy and will cause radioactivity.
HELP ME NOW PLZ
What is the speed of a boy moving around a circular park of
radius 6 m if he goes once around the park in 20 s?
A-1.88m/s
B-3.76m/s
C-5.65m/s
D-None of the above
Answer: 1.88 m/s
Explanation:
The speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.
What is speed?Speed is a measurement of how quickly an object's distance traveled changes. Speed is a scalar, which implies it has magnitude but no direction as a unit of measurement.
A thing that moves quickly and with great speed, covering a lot of ground in a short time. On the other hand, a slow-moving object traveling at a low speed covers a comparatively small distance in the same amount of time.
Given information:
The radius of the circular park, r = 6 m,
The time is taken to cover one round, t = 20s,
The total distance covered by the boy is equal to the circumference of the park, so
d = 2[tex]\pi[/tex]r,
[tex]d = 2*3.14*6\\d = 37.68 m[/tex]
Now,
the speed of the boy, s = [tex]37.68/20[/tex] ,
s = 1.88 m/s
Therefore, the speed of the boy moving around a circular park of radius 6 m and taking time 20 seconds is 1.88 m/s.
To know more about speed:
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An 5-kg animal accelerates from rest to 10 m/s in 10 m and encounters an average drag force of 12 N. What is the average power output in Watts if this takes 2.0 seconds
Answer:
60 watts
Explanation:
Given that
Mass of the animal, m = 5 kg
Velocity of the animal, v = 10 m/s
Distance moved by the animal, d = 10 m
Drag force, F(d) = 12 N
Time taken, t = 2 seconds
To start with, we need to find the power output in itself before proceeding to find the average power output. And as such, we have
Power = Force * Distance/Time
But Distance/Time is velocity, so
Power = Force * Velocity
Power = 12 * 10
Power = 120 W.
We then use this power gotten to find the average power output.
Power(avg) = P/t
Power(avg) = 120 / 2
Power(avg) = 60 Watts.
Therefore, the average power output is found to be 60 Watts
Given a force of 100N and an acceleration of 5 m/s2 , what is the mass?
Answer:
20kg
Explanation:
Given parameters:
Force = 100N
Acceleration = 5m/s²
Unknown:
Mass = ?
Solution:
According to Newton's second law of motion:
Force = mass x acceleration;
So;
Mass = [tex]\frac{force }{acceleration}[/tex]
Mass = [tex]\frac{100}{5}[/tex] = 20kg
Which one of the following is insoluble in water?
Food coloring
Lemon slices
Rock salt
White vinegar
Answer:
Lemon slices is the correct answer
Answer:
food coloring
Explanation:
i think food coloring is because it's just water with food coloring and that's it
Characteristics of good home insulation :
Answer:
Explanation:
all
What are some negative impacts of land pollution on humans?
Answer:
Land pollution touches essentially every area of the living world, including: Water that isn't safe to drink. Polluted soil, which leads to a loss of fertile land for agriculture. Climate change, which causes an onslaught of disastrous problems, including flash floods and irregular rainfalls.
Explanation:
HOPE THIS HELPS!!!!!!
Answer:
Look at any ecosystem and there could be multiple forms of contamination—streams full of toxic chemicals from industrial processes, rivers overloaded with nutrients from farms, trash blowing away from landfills, city skies covered in smog. Even landscapes that appear pristine can experience the effects of pollution sources located hundreds or thousands of miles away.
Pollution may muddy landscapes, poison soils and waterways, or kill plants and animals. Humans are also regularly harmed by pollution. Long-term exposure to air pollution, for example, can lead to chronic respiratory disease, lung cancer and other diseases. Toxic chemicals that accumulate in top predators can make some species unsafe to eat. More than one billion people lack access to clean water and 2.4 billion don’t have adequate sanitation, putting them at risk of contracting deadly diseases.
Air pollution brings to mind visions of smokestacks billowing black clouds into the sky, but this pollution comes in many forms. The burning of fossil fuels, in both energy plants and vehicles, releases massive amounts of carbon dioxide into the atmosphere, causing climate change. Industrial processes also emit particulate matter, such as sulfur dioxide, carbon monoxide and other noxious gases. Indoor areas can become polluted by emissions from smoking and cooking. Some of these chemicals, when released into the air, contribute to smog and acid rain. Short term exposure to air pollution can irritate the eyes, nose and throat and cause upper respiratory infections, headaches, nausea and allergic reactions. Long-term exposures can lead to chronic respiratory disease, lung cancer, and heart disease. Long-term exposures also can lead to significant climatic changes that can have far reaching negative impacts on food, water and ecosystems. #SAVE OUR WORLD
did sans from Undertale really die or was he just trolling
Answer:
I think he was just trolling.
Explanation:
They don't give out any good reasons or evidence about him dying. I think they are just pretending. You tell me tho.... Many people think he did die, while others think that he didnt.
What do you think?!
How can magnets cause objects to have kinetic energy?
Answer:
If there is a system of magnets being held in place, there is potential energy. When you let go the potential energy makes to kinetic energy and the magnets move.
Magnets cause objects to have kinetic energy as a result of the magnetic
force present in it.
Magnets is a material which has a strong metallic field which attracts
ferromagnetic substances such as steel, iron etc.
When the magnets are put near these substances , the magnets attract them and causes them to move towards its direction . The magnets causes the conversion of the potential energy into kinetic energy through the strong metallic field.
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Use of lubricants increase efficency of machine
Answer:
Lubrication reduces friction and allows moving machine parts to slide smoothly past each other. Selecting the appropriate lubrication solution can help reduce premature bearing failures and increase machine uptime, productivity and energy efficiency.
Explanation:
____energy is from the movement of electrons.
A. gravitational
B. chemical
C. electrical
D. nuclear
Answer:
C. electrialExplanation:
I hope l helped you. Please follow me. ❤❤❤❤A clock is designed that uses a mass on the end of a spring as a timing mechanism. If the oscillation time needed is exactly one second, what is the spring constant required if the mass is 1.3 kg
Answer:
The value is [tex]k = 51.34 \ N/ m[/tex]
Explanation:
From the question we are told that
The mass is [tex]m = 1.3 \ kg[/tex]
The needed oscillation time is [tex]T = 1 \ s[/tex]
Generally the spring constant is mathematically represented as
[tex]k = \frac{4 \pi^2 * m }{ T^2}[/tex]
=> [tex]k = \frac{4* 3.142^2 * 1.3 }{ 1^2}[/tex]
=> [tex]k = 51.34 \ N/ m[/tex]
To understand the meaning of the variables that appear in the equations for rotational kinematics with constant angular acceleration. Rotational motion with a constant nonzero acceleration is not uncommon in the world around us. For instance, many machines have spinning parts. When the machine is turned on or off, the spinning parts tend to change the rate of their rotation with virtually constant angular acceleration. Many introductory problems in rotational kinematics involve motion of a particle with constant, nonzero angular acceleration. The kinematic equations for such motion can be written as
Answer:
ω = ω₀ + α t
ω² = ω₀² + 2 α θ
θ = θ₀ + ω₀ t + ½ α t²
Explanation:
Rotational kinematics can be treated as equivalent to linear kinematics, for this change the displacement will change to the angular displacement, the velocity to the angular velocity and the acceleration to the angular relation, that is
x → θ
v → ω
a → α
with these changes the three linear kinematics relations change to
ω = ω₀ + α t
ω² = ω₀² + 2 α θ
θ = θ₀ + ω₀ t + ½ α t²
where it should be clarified that to use these equations the angles must be measured in radians
How much is a ball that is tethered to a post accelerating if its linear speed is 3.5 m/s and the ball is 0.91 meters away from the pole? a = v^2 / r
Answer:
[tex]a_{c} = 13.46\ m/s^2[/tex]
Explanation:
The motion of the tethered ball around the pole can be modeled as uniform circular motion. The acceleration of the objects executing uniform circular motion is due to the change in direction of their velocity. This is called centripetal acceleration. It is given by the following formula:
[tex]a_{c} = \frac{v^2}{r}[/tex]
where,
ac = centripetal acceleration = ?
v = speed of ball = 3.5 m/s
r = distance of ball from center of rotation = 0.91 m
Using these values in equation, we get:
[tex]a_{c} = \frac{(3.5\ m/s)^2}{0.91\ m}\\\\a_{c} = 13.46\ m/s^2[/tex]
A boy on a bicycle approaches a brick wall as he sounds his horn at a frequency 400 Hz. The sound he hears reflected back from the wall is at a frequency 408 Hz. At what speed is the boy riding his bicycle toward the wall
Answer:
6.8 m/s
Explanation:
To solve this, we would use the Doppler's Effect. Doppler's effect is represented by the formula
f = [(g + vr)/(g + vs)].fo, where
f = observed frequency, 408 Hz
g = speed of sound in air, 340 m/s
vr = velocity of the receiver
vs = velocity of the source, 0 m/s
fo = source frequency, 400 Hz
Now, applying the values to the equation, we have
408 = [(340 + vr)/(340 + 0) * 400
408/400 = (340 + vr)/340
1.02 * 340 = 340 + vr
346.8 = 340 + vr
vr = 346.8 - 340
vr = 6.8 m/s
Therefore the speed at which the boy is riding his bicycle towards the wall is 6.8 m/s
The pendulum consists of two slender rods AB and OC which each have a mass of 3 kg/m. The thin plate has a mass of 10 kg/m2. Determine the location of the center of mass G of the pendulum, then calculate the moment of inertia of the pendulum about an axis perpendicular to the page and passing through G.
Answer:
the answer is below
Explanation:
The diagram of the problem is given in the image attached.
Mass of rod AB = (0.4 m + 0.4 m) * 3 kg/m = 2.4 kg
Mass of rod OC = (1.5 m) * 3 kg/m = 4.5 kg
Mass of plate = 10 kg/m²[ (π* 0.3²) - (π* 0.1²)] = 2.513 kg
The center of mass is:
[tex]\hat{y}[2.4+2.513+4.5]=(0.75*4.5)+(2.513*0.5)\\\\\hat{y}=0.839\\\\I_{AB}=\frac{1}{12}*2.4*(0.4+0.4)^2= 0.128\ kg/m^2\\\\I_{OC}=\frac{1}{12}*4.5*(1.5)^2= 3.375\ kg/m^2\\\\I_{Gplate}=\frac{1}{2}*(\pi*0.3^2*10)*(0.3)^2-\frac{1}{2}*(\pi*0.1^2*10)*(0.1)^2= 0.126\ kg/m^2\\\\I_{plate}=I_{Gplate}+md^2=0.126+2.513(1.8^2)=8.27\ kg/m^2\\\\I_o=I_{plate}+I_{AB}+I_{OC}\\\\I_{o}=0.128+3.375+8.27=11.773\ kg/m^2 \\\\I_G=I_o-m_{tot}\hat{y}^2\\\\I_G=11.773-(9.413*0.839^2)\\\\I_G=5.147\ kg/m^2[/tex]
A large pendulum with a 200-lb gold-plated bob 12 inches in diameter is on display in the lobby of the United Nations building. The pendulum has a length of 75 ft. It is used to show the rotation of the Earth-for this reason it is referred to as a Foucault pendulum. What is the least amount of time it takes for the bob to swing from a position of maximum displacement to the equilibrium position of the pendulum?
Answer:
2.4s
Explanation:
The length of the pendulum = 75ft
Diameter d = 12 inches
The time period of the pendulum is given as
T = 2pi(L/g)^1/2
Then the time it takes to move from displacement to equilibrium is given as:
t = T/4
= (Pi/2)*(L/g)^1/2
= pi/2 x [(75x0.3048)/9.81]^0.5
= 1.57x[22.86/9.81)^0.5
= 2.4s
2.4 seconds is the least amount of time that it would take.
In which reaction are the atoms of elements rearranged?
A. A neutron fuses with hydrogen-1 to form hydrogen-2.
B. Uranium-235 breaks apart into cesium, rubidium, and two
neutrons.
C. A neutron fuses with uranium-238 to form uranium-239.
D. Hydrogen combines with oxygen to form water.
Answer:
D. Hydrogen combines with oxygen to form water.
Explanation:
Hydrogen combining with oxygen to form water is a typical example of chemical reaction.
During a chemical reaction, atoms of elements are rearranged. Most chemical reactions obey the law of conservation of mass which states that "matter is neither created nor destroyed in a chemical reaction but atoms are simply rearranged".
The other choices given are nuclear reactions. In such reactions, atoms are not rearranged but are simply destroyed and made in the process.
Answer:
D.) Hydrogen combines
Explanation:
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School bus drivers are extra careful when they cross railroad tracks. They stop before they cross railroad tracks to be sure that there is no train coming. Yet, trains typically move more slowly through towns than cars do. If trains usually move more slowly than cars, why can they do more damage if they hit something in their path?
Answer:
because trains are bigger and heavier than cars.
Explanation:
a 0.8 ,^3 insulated rigid tank contains 1.54 kg of carbon dioxide at 100 kPa. Now paddle wheel work is done on the system until pressure in the tank rises to 135 kpa assuming the ideal gas model and negligible kinetic and potential energy effects determine the paddle wheel work dine during the process and the energychange during this process
Answer:
The answer is "[tex]W= 100.44 \ KJ\ \ \ \W_{win}=7.23 \ KJ[/tex]"
Explanation:
Please find the complete question in the attached file.
From of the ideal gas relation that initial and the last temperatures were determined:
[tex]T_1 = \frac{P_1 V}{m R}[/tex]
[tex]= \frac{100 \times 0.8}{1.54 \times 0.1889} \\\\ = 275 \ K[/tex]
[tex]T_2 = \frac{P_2 V}{m R}[/tex]
[tex]= \frac{135 \times 0.8}{1.54 \times 0.1889} \\\\ = 317 \ K[/tex]
In the initial and final states, the internal energies for given temperatures are described from A-20 by means of intelmpolation and divided by the carlxon molar mass.
[tex]u_1 = 141.56 \frac{KJ}{kg}\\\\u_2 = 206.78 \frac{KJ}{kg}[/tex]
The real job is just the difference between internal energies:
[tex]W = m(u_2 - u_1) \\\\[/tex]
[tex]= 1.54(206.78 -141.56) \ kJ \\\\ =100.44 \ kJ[/tex]
In the initial and final states, the zero entries are as determined as internal energies:
[tex]S_1^{\circ} =4.788 \frac{KJ}{kg K}\\\\S_2^{\circ} =5.0478 \frac{KJ}{kg K}[/tex]
From its energy increase, the minimum work required is determined:
[tex]W_{min} = m(u_2-u_1 - T_0(s_2 -S_1))\\\\=W-mT_0(S_2^{\circ}- S_1^{\circ} -R \In \frac{P_2}{P_1})\\\\= 100.44kJ -1.54 \times 298( 5.0478-4.788-0.1889 \In \frac{135}{100})\\\\=7.23\ KJ\\[/tex]
which button allow you to move the text enter to a higher heading level
Answer:
The entry level is the basic part of any text or power point which needs to be pushed to the higher levels for reading the entire content
Three runners compete in a 400m race on an oval-shaped running track. At a certain time, one runner is 15m away from the finish line. Which term describes the finish line?
Answer:
Reference point.
Explanation:
Motion can be defined as a change in location (position) with respect to a reference point.
This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.
In this scenario, three runners compete in a 400m race on an oval-shaped running track. At a certain time, one runner is 15m away from the finish line. Thus, the term which best describes the finish line is a reference point.
A reference point can be defined as a fixed point that typically marks the position from which a body starts its motion or change its location.
Question 1 of 25
Two asteroids with masses 3.71 x 10 kg and 1.88 x 104 kg are separated by
a distance of 1,300 m. What is the gravitational force between the asteroids?
Newton's law of gravitation is F gravity
Gm, 2 The gravitational
constant Gis 6.67 x 10-11 Nm²/kg?
A. 275 x 10"N
B. 4.13 x 10°N
C. 2.04 x 10°N
O D. 3.58 x 10-N
SUBMIT
Answer:
2.753*10^-11N
Explanation:
According to Newton's law of gravitation, the force between the masses is expressed as;
F = GMm/d²
M and m are the distances
d is the distance between the masses
Given
M = 3.71 x 10 kg
m = 1.88 x 10^4 kg
d = 1300m
G = 6.67 x 10-11 Nm²/kg
Substitute into the formula
F = 6.67 x 10-11* (3.71 x 10)*(1.88 x 10^4)/1300²
F = 46.52*10^(-6)/1.69 * 10^6
F = 27.53 * 10^{-6-6}
F = 27.53*10^{-12}
F = 2.753*10^-11
Hence the gravitational force between the asteroid is 2.753*10^-11N
The Mars Curiosity rover was required to land on the surface of Mars with a velocity of 1 m/s. Given the mass of the landing vehicle and parachute is 2270 kg, the drag coefficient is effectively 0.5, the atmosphere density is 0.71 that of Earth (take Earth atmosphere density as 1.2 kg/m3), and the Martian gravitational acceleration is 3.689 m/s2, find the required total frontal area (in m2) of the lander plus a parachute to land at the given velocity. Assume the landing vehicle has achieved terminal velocity as it falls through the Martian atmosphere.
Answer:
The value is [tex]A = 39315 \ m^2[/tex]
Explanation:
From the question we are told that
The velocity which the rover is suppose to land with is [tex]v = 1 \ m/s[/tex]
The mass of the rover and the parachute is [tex]m = 2270 \ kg[/tex]
The drag coefficient is [tex]C__{D}} = 0.5[/tex]
The atmospheric density of Earth is [tex]\rho = 1.2 \ kg/m^3[/tex]
The acceleration due to gravity in Mars is [tex]g_m = 3.689 \ m/s^2[/tex]
Generally the Mars atmosphere density is mathematically represented as
[tex]\rho_m = 0.71 * \rho[/tex]
=> [tex]\rho_m = 0.71 * 1.2[/tex]
=> [tex]\rho_m = 0.852 \ kg/m^3[/tex]
Generally the drag force on the rover and the parachute is mathematically represented as
[tex]F__{D}} = m * g_{m}[/tex]
=> [tex]F__{D}} = 2270 * 3.689[/tex]
=> [tex]F__{D}} = 8374 \ N[/tex]
Gnerally this drag force is mathematically represented as
[tex]F__{D}} = C__{D}} * A * \frac{\rho_m * v^2 }{2}[/tex]
Here A is the frontal area
So
[tex]A = \frac{2 * F__D }{ C__D} * \rho_m * v^2 }[/tex]
=> [tex]A = \frac{2 * 8374 }{ 0.5 * 0.852 * 1 ^2 }[/tex]
=> [tex]A = 39315 \ m^2[/tex]
A 3000-kg truck moving with a velocity of 25 m/s hits a 1000-kg parked car. The impact causes the 1000-kg car to be set in motion at 7 m/s. What is the velocity of the truck after the collision?
Answer:
v₃ = 22.67 [m/s]
Explanation:
In order to solve this problem, we must use the principle of conservation of the quantity of linear momentum. Where momentum is conserved before and after the collision, i.e. remains the same.
The terms on the left of the equation represent the amount of linear momentum before the collision and the members on the right represent the momentum after the collision.
[tex](m_{1}*v_{1})+(m_{2}*v_{2})=(m_{1}*v_{3})+(m_{2}*v_{4})[/tex]
where:
m₁ = mass of the truck = 3000 [kg]
m₂ = mass of the car = 1000 [kg]
v₁ = velocity of the truck before the coliision = 25 [m/s]
v₂ = velocity of the car parked = 0 (without movement)
v₃ = velocity of the truck after the collision [m/s]
v₄ = velocity of the car after the collision = 7 [m/s]
Now replacing:
[tex](3000*25)+(1000*0)=(3000*v_{3})+(1000*7)\\75000-7000 = 3000*v_{3}\\v_{3}=22.67 [m/s][/tex]