The question is incomplete. The complete question is :
A car is stopped at a traffic signal. A second car rear-ends the first car. From the crush of the two vehicles, it is estimated that the second car was traveling at 15 mph when it impacted the first car. If the second car laid down 166 feet of skid marks before the crash took place, how fast was the second car traveling when its brakes were locked up? The approach to the intersection where the accident took place is on a 2.5 percent downgrade. Assume the AASHTO recommended deceleration rate of [tex]$11.2 \ ft/s^2.$[/tex]
Solution :
From the equation, the skid distance is given by
[tex]$S=\frac{u_i^2-u_f^2}{2g\left(\frac{a_d}{g}+h\right)}$[/tex]
Here, [tex]$a_d$[/tex] = deceleration rate, [tex]$11.2 \ ft/s^2.$[/tex]
h = [tex]$-\frac{2.5}{100}$[/tex] = -0.025
[tex]$u_i$[/tex] = initial speed of the car
[tex]$u_f$[/tex] = speed when impacted
Therefore,
[tex]$166=\frac{u_i^2-(15 \times 1.467)^2}{2\times 32.2\left(\frac{11.2}{32.2}+0.025\right)}$[/tex]
[tex]$\Rightarrow u_i^2 = 3935.36$[/tex]
[tex]$\Rightarrow u_i = 62.73 \ ft/s$[/tex]
or [tex]$ u_i = \frac{62.73}{1.467} $[/tex]
[tex]$ u_i = 42.76 \ mph $[/tex]
A crude oil storage tank initially contains 1000 of crude oil. Oil is pumped into the tank through a pipe at a rate of 2 and out of the tank at a velocity of 1.5 m/s through another pipe having a diameter of 0.15m. The crude oil has a specific volume of 0.0015 . Determine:a) The mass of oil in the tank, in kg, after 24 hoursb) The volume of oil in the tank, in , at that time
This question is incomplete, the complete question is;
A crude oil storage tank initially contains 1000 m³ of crude oil. Oil is pumped into the tank through a pipe at a rate of 2 m³/min and out of the tank at a velocity of 1.5 m/s through another pipe having a diameter of 0.15m. The crude oil has a specific volume of 0.0015 m³/kg .
Determine : a) The mass of oil in the tank, in kg, after 24 hours b) The volume of oil in the tank, in m³, at that time ( after 24hrs )
Answer:
a) The mass of oil in the tank after 24hrs is 1059852.6667 kg
b) The volume of oil in the tank, in m³, at that time is 1589.779 m³
Explanation:
Given that;
volume of tank v = 1000 m³
Discharge (AV)₁ = 2 m³/min
specific volume (v) = 0.0015 m³/kg
a)
for one inlet, one exit control volume, we have]
d(mc[tex]_v[/tex])/dt = "m[tex]_i[/tex] - "m[tex]_e[/tex]
"m[tex]_i[/tex] = (AV)₁ / v
"m[tex]_i[/tex] = 2 / 0.0015
"m[tex]_i[/tex] = 1333.33 kg/min = ( 1333.33 kg/min × 60 ) = 80,000 kg/hr
"m[tex]_e[/tex] = AV₂/v
AREA A = πr² = π(0.15m/2)²
so
"m[tex]_e[/tex] = ( π(0.15m/2)² × 1.5 m/s ) / 0.0015m³/kg
"m[tex]_e[/tex] = 17.6714 kg/s = (17.6714 kg/s × 60 × 60 ) = 63,617.25 kg/hr
d(m[tex]_{cv}[/tex])/dt = 80000 - 63,617.25 = 16382.75 kg/hr
now after 24 hours, the mass of the crude oil tank is;
mc[tex]_v[/tex]( 24 ) = ( 16382.75 × 24 ) + mass initially contained
so initial mass m[tex]_i[/tex] = volume / specific volume
initial mass m[tex]_i[/tex] = V / v = 1000 / 0.0015 = 666,666.6667 kg
Total mass = m[tex]_i[/tex] + mc[tex]_v[/tex]
Total mass = 666,666.6667 kg + (16382.75 × 24)
Total mass = 1059852.6667 kg
Therefore, The mass of oil in the tank after 24hrs is 1059852.6667 kg
b)
Volume will be;
V = total mass × density
V = 1059852.6667 kg × 0.0015 m³/kg
V = 1589.779 m³
Therefore, The volume of oil in the tank, in m³, at that time is 1589.779 m³
When will heat STOP flowing
between two objects?
A. When one object is significantly
warmer than the other
B. When one object is significantly cooler
than the other
C. Never
D. When both objects reach the same
temperature
Answer: D. When both objects reach the same temperature.
Explanation: When will heat flow between the objects stop? Heat will always flow from the warmer object to the colder object. The heat transfer will stop when the two objects are at the same temperature and reach thermal equilibrium.
Answer: Heat will always flow from the warmer object to the colder object. The heat transfer will stop when the two objects are at the same temperature and reach thermal equilibrium.
so the answer to your question is c
Explanation:
Alternate current
Hello!
I need solve 2 questions, I tried but im so bad at physics :(
1. If the frequency in the network is 50Hz, what is the period of this voltage?
2. The effective voltage value in the network is 230V. What is its maximum value?
I would like an explanation with a calculation for my understanding!!
Thanks in advance you all!
sorry bro but i don't know his i am also bad
Explanation:
but maybe you can you the formula of volatage as well as
The force of friction depends upon
Answer:
ask internet?
Explanation:
easy .....
..
An important news announcement is transmitted by radio waves to people who are 46 km away, sitting next to their radios, and by sound waves to people sitting across the newsroom, 2.1 m from the newscaster. Take the speed of sound in air to be 348 m/s. What is the difference in time that the message is received
Answer:
[tex]0.005847\ \text{s}[/tex]
Explanation:
Radio waves travel at the speed of light
[tex]c[/tex] = Speed of light = [tex]3\times 10^8\ \text{m/s}[/tex]
[tex]d_r[/tex] = Distance between two radios = 46 km
[tex]v[/tex] = Speed of sound in air = 348 m/s
[tex]d_s[/tex] = Distance sound travels across the newsroom = 2.1 m
Time taken by the radio signal to reach the required location is
[tex]t_r=\dfrac{d_r}{c}\\\Rightarrow t_r=\dfrac{46\times 10^3}{3\times 10^8}\\\Rightarrow t_r=0.000153\ \text{s}[/tex]
Time taken by sound to reach the required location is
[tex]t_s=\dfrac{d_s}{v}\\\Rightarrow t_s=\dfrac{2.1}{348}\\\Rightarrow t_s=0.006\ \text{s}[/tex]
The time difference is
[tex]t_s-t_r=0.006-0.000153=0.005847\ \text{s}[/tex]
The difference in time that the message is received is [tex]0.005847\ \text{s}[/tex].
2 points
13. The law of conservation of mass can be demonstrated by a chemical
reaction. Which of the following models of a chemical reaction best
represents the law of conservation of mass?
A
C
B
D.
8
8.
a.
Ο Ο Ο Ο
Answer:
A
Explanation:
the mass in the option a is conserved of two elements
5. It takes
to get a job done.
Answer:
determination
Explanation:
. Four railroad cars, each of mass 2.50 104 kg, are coupled together and coasting along horizontal tracks at a speed of vi toward the south. A very strong but foolish movie actor, riding on the second car, uncouples the front car and gives it a big push, increasing its speed to 4.00 m/s southward. The remaining three cars continue moving toward the south, now at 2.00 m/s. (a) Find the initial speed of the cars. (b) How much work did the actor do
Answer:
a) v₀ = 2.5 m / s, heading south.
b) W = 1,219 10⁵ J
Explanation:
a) For this exercise we can use the conservation of the moment, we create a system formed by all the 4 cars, in this case when the last one separates the forces are intense and the moment is conserved
initial instant. Before separation
p₀ = M v₀
final instant. When uncoupling the last car
p_f = 3m v₁ + m v₂
where they indicate that the speed of the wagons is v₁ = 2.00 m / s and the speed of the last wagon is v₂ = 4.00 m / s
the total mass is M = 4m
how the moment is preserved
p₀ = p_f
4m v₀ = 3m v₁ + mv₂
v₀ = ¾ v₁ + v₂ / 4
let's calculate
v₀ = ¾ 2 + ¼ 4
v₀ = 2.5 m / s
heading south.
b) work is equal to the change in kinetic energy
W = ΔK = K_f -K_o
W = ½ m v_f² - ½ m v₀²
W = ½ m (v_f² -v₀²)
W = ½ 2.50 10⁴ (4² - 2.5²2)
W = 1,219 10⁵ J
Help please thank you
anser: 27s PoP
Explanation:
1 is the force, so the equal antiforce will be 1. weight of car divided by force from engine
34 pop / s = 129
27pOp
g Drop the object again and carefully observe its motion after it hits the ground (it should bounce). (Consider only the first bounce and do NOT assume the total energy is the same as the total energy of the object before it hits the ground.) a. List the quantities that you need to know to determine the total energy of the object after it hits the ground. b. Record your measurements and describe how you measured them. c. Calculate the total energy of the object after it hit the ground. Your final answer: ______________ d. Determine whether or not the object’s energy was conserved when it hit the ground. If it was not conserved, explain where the energy went.
Answer:
a) quantity to be measured is the height to which the body rises
b) weighing the body , rule or fixed tape measure
c) Em₁ = m g h
d) deformation of the body or it is transformed into heat during the crash
Explanation:
In this exercise of falling and rebounding a body, we must know the speed of the body when it reaches the ground, which can be calculated using the conservation of energy, since the height where it was released is known.
a) What quantities must you know to calculate the energy after the bounce?
The quantity to be measured is the height to which the body rises, we assume negligible air resistance.
So let's use the conservation of energy
starting point. Soil
Em₀ = K = ½ m v²
final point. Higher
Em_f = U = mg h
Em₀ = Em_f
Em₀ = m g h₀
b) to have the measurements, we begin by weighing the body and calculating its mass, the height was measured with a rule or fixed tape measure and seeing how far the body rises.
c) We use conservation of energy
starting point. Soil
Em₁ = K = ½ m v²
final point. Higher
Em_f = U = mg h
Em₁ = Em_f
Em₁ = m g h
d) to determine if the energy is conserved, the arrival energy and the output energy must be compared.
There are two possibilities.
* that have been equal therefore energy is conserved
* that have been different (most likely) therefore the energy of the rebound is less than the initial energy, it cannot be stored in the possible deformation of the body or it is transformed into heat during the crash
Almost all cells are microscopic.
True
False
ill give brainlist’s if u give them back for answering this
Answer:
It's True...................
When a baseball hits a
baseball glove, what is the
reaction force?
A. The ball pushes onto the glove.
B. The glove pushes against the ball.
C. The ball falls to the ground.
at for every
reaction.
all at the
his glove.
Marcy pulls a backpack on a wheels down the 100m hall. The 60N force is applied at an angle of 30° above the horizontal. How much work is done by Marcy?
Answer:
Work= Fcos∆×S
W=60N×cos 30⁰×100
W=60×0.866×100=5196.1J
PLEASE GIVE BRAINLIEST
Which phrase best completes the diagram?
Goals of Social Policy:
Providing citizens with an education ➡️Ensuring the safety of citizens➡️?
A. Helping people who live in poverty.
B. Increasing aid to foreign countries.
The correct answer is:
A. Helping people Who live in poverty
Answer:
Did you ask the question and answer it for yourself?
Answer:
Your amazing thank you, A was right.
finger bones do not have joints true or false
Explanation:
Finger bones have joints.
Answer: true , finger bones have joints
Explanation:
define prism and itz colo
Answer:
A prism is a piece of glass or plastic in the shape of a triangle.
Explanation:
The colors of the rainbow in order are: red, orange, yellow, green, blue, indigo, and violet.
A fisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. It takes a time of 2.10 s for the boat to travel from its highest point to its lowest, a total distance of 0.700 m. The fisherman sees that the wave crests are spaced a horizontal distance of 6.10 m apart. A. How fast are the waves traveling?B. What is the amplitude of each wave? C. If the total vertical distance traveled by the boat were 0.500 , but the other data remained the same, how fast are the waves traveling? D. If the total vertical distance traveled by the boat were 0.500 , but the other data remained the same, what is the amplitude of each wave?
Answer:
a) v = 2.9 m / s, b) A = 0.350 m, c) v = 2.9 m / s, d) A = 1.00 m
Explanation:
The oscillatory motion is described by the expression
x = A cos (wt + Ф)
the wavelength which is the distance for the wave to repeat and the frequency which is the number of times a wave oscillates per unit of time
a) In this part they ask us for the speed of the wave.
Let's use the relationship between speed, wavelength and frequency
v = λ f
For the wavelength they indicate that the distance between two crest is 6.1 m
λ / 2 = 6.10
λ = 12.20 m
They give us the period of the wave is the time it takes to return to the same point, in this case they give half a period
A / 2 = 2.10
A = 4.20 me
f = 1 / t
f = ¼, 2
f = 0.238 Hz
let's calculate
v = 12.20 0.238
v = 2.9 m / s
b) the amplitude of the wave, is the distance from zero to some maximum
2A = 0.700
A = 0.350 m
c) the speed of the wave is not function of the amplitude, so the speed is the same
v = 2.9 m / s
d) the amplitude is
2A = 0.50
A = 1.00 m
on which principle thermometer is based?
Answer:
Thermal Expansion
Explanation:
These liquid thermometers are based on the principal of thermal expansion. When a substance gets hotter, it expands to a greater volume. Nearly all substances exhibit this behavior of thermal expansion. It is the basis of the design and operation of thermometers.
In certain cases, using both the momentum principle and energy principle to analyze a system is useful, as they each can reveal different information. You will use the both momentum principle and the energy principle in this problem.
A satellite of mass 3500 kg orbits the Earth in a circular orbit of radius of 7.3 106 m (this is above the Earth's atmosphere).The mass of the Earth is 6.0 1024 kg.
What is the magnitude of the gravitational force on the satellite due to the earth?
F= ________N
Using the momentum principle, find the speed of the satellite in orbit. (HINT: Think about the components of (dp^^\->)\/(dt) parallel and perpendicular to p^^\->.)
v = ________ m/s
Using the energy principle, find the minimum amount of work needed to move the satellite from this orbit to a location very far away from the Earth. (You can think of this energy as being supplied by work due to something outside of the system of the Earth and the satellite.)
work= ________J
Answer:
A) F_g = 26284.48 N
B) v = 7404.18 m/s
C) E = 19.19 × 10^(10) J
Explanation:
We are given;
Mass of satellite; m = 3500 kg
Mass of the earth; M = 6 x 10²⁴ Kg
Earth circular orbit radius; R = 7.3 x 10⁶ m
A) Formula for the gravitational force is;
F_g = GmM/r²
Where G is gravitational constant = 6.67 × 10^(-11) N.m²/kg²
Plugging in the relevant values, we have;
F_g = (6.67 × 10^(-11) × 3500 × 6 x 10²⁴)/(7.3 x 10⁶)²
F_g = 26284.48 N
B) From the momentum principle, we have that the gravitational force is equal to the centripetal force.
Thus;
GmM/r² = mv²/r
Making v th subject, we have;
v = √(GM/r)
Plugging in the relevant values;
v = √(6.67 × 10^(-11) × 6 x 10²⁴)/(7.3 x 10⁶))
v = 7404.18 m/s
C) From the energy principle, the minimum amount of work is given by;
E = (GmM/r) - ½mv²
Plugging in the relevant values;
E = [(6.67 × 10^(-11) × 3500 × 6 × 10²⁴)/(7.3 x 10⁶)] - (½ × 3500 × 7404.18)
E = 19.19 × 10^(10) J
A sound having a frequency of 299 Hz travels through air at 332 m/s.
What is the wavelength of the sound? Answer in units of m.
Answer:
1.11 m.
Explanation:
Why?
The speed for a wave is done by the equation: v = f * w. Because the frecuency tells us about how many cycles the wave makes each time, but for each cycle the wave runs certain distance, given for the wavelenght. If you isolate the letter w you get the value just doing a ratio.
v = speed
f = frecuency
w = wavelenght
w = v / f
Using Bernoulli's equation Calculate the percentage increase in the speed of the air on the upper surface of the wings relative to the lower surface,if aircraft mass is 3.3×10^5kg,Total wing area is 500m^2 ,Flight level speed of 9600km/h and density of air is 1.2kgm^-3??
Explanation:
3d7eei4rueiuxx7ex5x775xe
Which of the following is an example of an ascribed status?
Multiple Choice
1. musician
2. poor
3. female
4. college student
From the given options the best example of an ascribed status will be poor. Hence, option 2 is the correct one.
What is ascribed status?In sociology, the term "ascribed status" refers to a human's social standing as it is either allocated to them at birth or implicitly assumed in later life. The position of status is one that a person neither chooses for themselves nor earns. Instead, the position is decided upon in accordance with cultural and societal norms and standards. No matter how hard you try or how much you want to, these slots are filled. These fixed social designators are independent of the favorable or unfavorable stereotypes associated with one's assigned statuses and stay unchanged throughout a person's life.
Every society engages in the process of classifying people into categories based on factors including gender, race, family history, and ethnicity. This process is cross-cultural.
To know more about ascribed status:
https://brainly.com/question/9382045
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Rank the following circuits in order from highest to lowest values of the current in the circuit.
i. a 1.4-Ω resistor connected to a 1.5-V battery that has an internal resistance of 0.10 Ω;
ii. a 1.8-Ω resistor connected to a 4.0-V battery that has a terminal voltage of 3.6 V but an unknown internal resistance;
iii. an unknown resistor connected to a 12.0-V battery that has an internal resistance of 0.20 Ω and a terminal voltage of 11.0 V.
a. (i), (iii), (ii)
b. (iii), (i), (ii)
c. (ii), (iii), (i)
d. (i), (ii), (iii)
e. (iii), (ii), (i)
f. (ii), (i), (iii)
Answer:
e)
Explanation:
Let's get first the values of the currents for the three cases.i)
The battery forms a series circuit with its internal resistance and the 1.4 Ω resistor. Since the current is the same at any point of the circuit, and the sum of all voltages along a closed circuit must be zero, we can apply Ohm's Law in each resistor, as follows:[tex]V = I*r_{i} + I*R_{1} (1)[/tex]
Replacing V, ri and R₁ by their values, we can solve for the current I as follows:[tex]I_{i} = \frac{V}{r_{int} + R_{i}} = \frac{1.5V}{0.1 \Omega + 1.4 \Omega} = 1.0 A (2)[/tex]
ii)
Since the voltage of the battery is 4.0 V (open circuit voltage), and it falls to 3.6 V when is connected to a 1.8Ω resistor, this means that the voltage through the resistor must be 3.6 V, due to the sum of all voltages along a closed circuit must be zero.So, we can find the current through the circuit, applying Ohm's Law to the 1.8Ω resistor, as follows:[tex]I_{ii} =\frac{V_{term} }{R_{ii} } =\frac{3.6V}{1.8 \Omega} = 2.0 A (3)[/tex]
iii)
Since the 12.0 V battery has a terminal voltage of 11.0 , this means that the voltage through the internal resistance of 0.2 Ω, must be 1.0 V.So we can find the current Iiii, applying Ohm's Law to the internal resistance value, as follows:[tex]I_{iii} =\frac{V-V_{term}}{r_{int} } =\frac{12.0 V- 11.0 V}{0.2 \Omega} =\frac{1.0V}{0.2\Omega} = 5.0 A (4)[/tex]
So, the highest current is the Iiii, followed by Iii and Ii, which is stated by e).Arrange the following substances from the lightest to the heaviest:
Cl2, CH4; H20; NH3, N2
A. H2O<NH,< N2 CH4Cl2
B. CH< NH< H-0< < Cl2
C. Ny< Cl< H2O< CH«<NH3
D. NH;< CH«< Cl< H2O< N2
molecular weights are written in the picture.
CH4<NH3<H2O<Cl2
ANSWER DIS ASAP FOR LUCK TMRW :}
List down ten situations that show how friction affects the movement of objects. I NEED THE ANSWER IN ONE MINUTE
Answer:
Walking –We can walk only if we apply frictional force. Friction is what holds your shoe to the ground. The friction present on the ice is very little, this is the reason why it is hard to walk on the slippery surface of the ice.
Writing – A frictional force is created when the tip of the pen comes in contact with the surface of the paper. Rolling friction is what comes into play while writing with a ballpoint pen while sliding friction arises when one writes with a pencil.
Skating – A thin film of water under the blade is necessary to make the skate slide. The heat generated by the skate blade rubbing against the surface of ice causes some of the ice to melt right below the blade where the skater glides over the ice. This water acts as a lubricant reducing friction.
Lighting a matchstick – When the head of the matchstick is rubbed against a rough surface, heat is generated and this heat converts red phosphorous to white phosphorous. White phosphorous is highly inflammable and the match stick ignites. Sometimes, matchsticks fail to ignite due to the presence of water. Water lowers friction.
Driving of the vehicle on a surface- While driving a vehicle, the engine generates a force on the driving wheels. This force initiates the vehicle to move forwards. Friction is the force that opposes the tyre rubber from sliding on the road surface. This friction avoids skidding of vehicles.
Applications of breaks in the vehicle to stop it- Friction braking is the most widely used braking method in vehicles. This process involves the conversion of kinetic energy to thermal energy by applying friction to the moving parts of a vehicle. The friction force resists the motion and in turn, generates heat. This conversion of energy eventually bringing the velocity to zero.
Flight of aeroplanes- Drag is the force that opposes the forward motion of the aeroplane. The friction which resists the motion of an object moving through a fluid or immobile in a moving fluid, as occurs when we fly a kite. The friction of the air is created as it meets and passes over an aeroplane and its components. Drag is generated by air impact force, skin friction and displacement of the air.
Drilling a nail into the wall- Friction is responsible for fixing of nails in a wall. As the nail is driven into the wall, the nearby material to the nail of the wall gets compressed. This exerts a force on the nail. This force is the friction that converts the normal force exerted by the compressed layers of the wall into the resisting shear force. In this manner the friction cause nails and screws to hold on to walls.
The dusting of the carpet by beating it with a stick- When the carpet is beaten with the stick, the dust comes out. The dust is carried off by the wind or falls on the floor. The carpet exhibits a little static friction that holds the dust to the carpet. When the carpet is beaten, it will overcome the friction and the carpet will move away from the dust making the carpet free from dust.
Sliding on a garden slide- We know that friction is a force that is present whenever two objects rub against each other. In case of a slide in the garden such as a slide and a person’s backside rub each other’s surface. Without friction, a slide would accelerate the rider too quickly, resulting in possible injury due to the fall. The friction reduces the velocity of the sliding person and makes him stop.
Hope that helps! :D Sorry if it's too lengthy...
Explanation:
Any magnet has two ends, each one called a(n)
Two coils of wire are placed close together. Initially, a current of 3.03 A exists in one of the coils, but there is no current in the other. The current is then switched off in a time of 3.03 x 10-2 s. During this time, the average emf induced in the other coil is 4.13 V. What is the mutual inductance of the two-coil system
Answer:
4.13 ×10^-2 H
Explanation:
mutual inductance of the two-coil system can be calculated using below expression
mutual inductance = (- E Δt)/ ΔIp
Where E= average emf induced
Δt= time
ΔIp= change in current
ΔIp=( 0s - 3.03 A)
Δt=3.03 x 10-2 s.
If we substitute the values into above expresion, we have,
E= 4.13 V.
mutual inductance = (- E Δt)/ ΔIp
= - (4.13 V × 3.03 x 10^-2 s.)/ ( 0s - 3.03 A)
= 4.13 ×10^-2 H
Hence, the mutual inductance of the two-coil system is 4.13 ×10^-2 H
What is the magnitude of the resultant vector? Round
your answer to the nearest tenth.
m
R
5 m
13 m
Intro
Done
Answer: 13.9 m
Explanation:
Answer:
13.9m
Explanation:
Answer on Edge
A 1,250 kg car is moving due to 6,500 N engine force. If the kinetic friction coefficient between the car and the road is 0.32, what is the car's acceleration?
A) 32m/s²
B) 200m/s²
C) 50m/s²
D) 2m/s²
Answer and I will give you brainiliest
Answer:
b i hope this is correct answee
[1 mark]
29. A ball rolls at a constant speed of 3.0 m/s for 8.0 seconds. How far does it roll in this time!
A. 2.7 m
B. 3.0 m
C. 8.0 m
D. 24.0 m
Please help me
Answer:
D. 24.0m
Explanation:
formula
S=d/t
s=speed
d=distance
t=time
s=3.0m/s
d=x
t=8.0s
s=d/t
d=s*t
d=3.0*8.0
d=24.0m