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]
PLEASE HELP ME WITH THIS ONE QUESTION
A mass on a spring oscillates with a frequency of 0.1 Hz. The mass is 10 kg. What is the spring constant of the spring?
The frequency of oscillation of a mass on a spring is given by the equation:
[tex]f = 1 / (2π) * sqrt(k / m)[/tex]
[tex]k = (1 / (2π)^2 ) * (0.1^2) * 10 kg[/tex]
[tex]k = 0.158 N/m[/tex]
The spring constant of the spring is 0.158 N/m.
What is a spring constant?The spring constant, also known as the spring rate or rate constant, is a measure of the stiffness of a spring. It represents the amount of force (in newtons) required to compress or stretch a spring a certain distance (in meters) from its equilibrium position. The spring constant is a proportionality constant that relates the force applied to a spring to the resulting displacement.
The spring constant is an important property of a spring because it determines how much force is required to compress or stretch the spring a certain distance. A spring with a higher spring constant will be stiffer, and will require more force to compress or stretch it a certain distance, while a spring with a lower spring constant will be more flexible and will require less force to compress or stretch it a similar distance.
It is represented by the letter 'k', the unit of spring constant is N/m (Newton per meter). The greater the spring constant, the stiffer the spring is, and the less it will deflect for a given force.
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That other answer is untrustworthy. It's probably a POS troll.
The real answer: 4 N/m
Currently, accepted theories DO NOT predict single existing particles having electrical charge equal *
a.half elementary charge
b.one elementary charge
c.two elementary charges
d.zero elementary charge
Answer
A. Half elementary charge
Explanation:
for the hypothetical salaries in the following
dataset, what is the average salary per year?
Data set of hypothetical salaries: $46,000 per year,
$20,000 per year, $33,000 per year, $27,000 per year,
$91,000 per year.
Answer: $43400 per year
Explanation:
The Data set of hypothetical salaries is given as:
$46,000 per year,
$20,000 per year,
$33,000 per year,
$27,000 per year,
$91,000 per year.
The average salary per year will be the addition of the salaries per year above which will then be divided by 5. This will be:
= ($46,000 + $20,000 + $33,000 + $27,000 + $91,000) / 5
= $217000/5
= $43400 per year
The average salary per year will be $43400
What are the three ways to electrify an object?
Almost all cells are microscopic.
True
False
ill give brainlist’s if u give them back for answering this
Answer:
It's True...................
A wave of frequency 500hz and wave length 50m is traveling into a medium, dertimine the speed of velocity of the wave. formula V=f×d.
Answer:
25000m/s
Explanation:
V=fd
V=(500)(50)
V=25000m/s
Ans
Sep 19, 2019 — Wave speed is the distance a wave travels in a given amount of time, such as the ... Wave speed is related to both wavelength and wave frequency. ... The equation for wave speed can be used to calculate the speed of a wave when both ... Frequency = SpeedWavelength or Wavelength = SpeedFrequency.
Explanation:
help, it's an emergency !!!!!!!
Three cars (car F, car G, and car H) are moving with the same velocity when the driver suddenly slams on the brakes, locking the wheels. The most massive car is car F, the least massive is car H, and all three cars have identical tires. (a) Which car travels the longest distance to skid to a stop? A) Car F B) Car G C) Car H D) They all travel the same distance in stopping. (b) For which car does friction do the largest amount of work in stopping the car? A) Car F B) Car G C) Car H D) The amount of work done by friction is the same for all cars.
Answer:
a) Option D
b) Option A
Explanation:
a) Option D
Because a massive car will have more inertia which will make the car move faster but a massive car simultaneously will have more friction thereby restricting its movement in the forward direction. Hence, all the three cars will move equal distance.
b) Option A, Car F
Being most massive car, the frictional force required to stop the car will be highest.
Define electromagnetism
Answer:
the phenomenon of the interaction of electric currents or fields and magnetic fields.
Which of the following technologies would produce the least energy in light
waves?
A. Ultraviolet disinfecting wand
B. Microwave industrial drying equipment
C. Radio-controlled toy airplane
D. Halogen lightbulb
Answer: C. Radio-controlled toy airplane
Explanation:
Just did the quiz
Radio-controlled toy airplane technologies would produce the least energy in light waves. Hence option C is correct.
Energy of the electromagnetic wave is directly proportional to frequency of the light wave. This relation is given by, E =hυ where h is planks constant and υ is frequency of light wave.
Remote of the radio controlled toy airplane produces radio waves to communicate between remote and the plane. Radio wave have high wavelength and low frequency, hence it has least energy as compare to UV light and and microwave light. Ultraviolet disinfecting wand produces ultraviolet light whose frequency is high than the microwave and radio waves.
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You hear the sound from a tuning fork vibrating at 483 Hz. You then hear the sound from a second tuning fork vibrating at 512 Hz. What is different about the sound waves created by these two tuning forks?
The second sound has a higher frequency and a shorter wavelength
The second sound has a higher frequency and a lower speed
The second sound has a higher frequency and a higher speed
The second sound has a higher frequency and a higher wavelength
The second sound has a higher frequency but the same wavelength
Answer:
tgggggg
Explanation:
A 1.0 kg ball falls from rest a distance of 19.6 m.
- What was its change in potential energy?
- What was its velocity after falling 19.6 m?
Answer:
192.08J
19.6m/s
Explanation:
Since there will be no potential energy when the ball is on the ground, the change in potential energy is equal to the potential energy at the start when the ball is 19.6m above the ground.
PE=mgh
=(1)(9.8)(19.6)
=192.08J
v²=u²+2as, where v is the final velocity, u is initial velocity, a is acceleration and s is distance. Initial velocity is 0 since it starts at rest.
v²=u²+2as
v²=0²+2(9.8)(19.6)
v=√384.16
=19.6m/s
who compose the Ghana national anthem
Answer:
Philip Gbeho
Explanation:
PLZ HELP PLZ ILL GIVE BRAINLIEST TO BEST ANSWERED
The Earth's gravity pulling on a skydiver: Contact or Non Contact
Friction from a car's brakes causing it to stop: Contact or Non Contact
The repulsive magnetic force between the north poles of two magnets: Contact or Non Contact
The attractive electrostatic force between an electrically charged balloon and a wall: Contact or Non Contact
Answer:
1.Contact because its a contact force
2 Contact because when the car is stopping it is coming in to contact with the ground.
3 non Contact because magnets don't need to have contact they pull
4 non Contact because its not a contact force
A substance is poured from one container to
another, but the shape does not change. What
state is it in?
Answer:
Its liquid because when you pour water into different cups of different sizes its still the same shape
Why do we use copper wiring?
Explanation:
The lower the level of resistivity the more electrical conductivity a metal has. Copper has low resistivity, and therefore is an excellent conductor. Copper is also less oxidative than other metals
Explain how the plants of a tropical rain forest contribute to the characteristic hot, humid weather associated with the area. Use details to support your answer.
Answer: The atmosphere of trophic rainforest is hot and humid due to high rate of transpiration.
Explanation:
The tropical rainforest is a biome which exhibit rich biodiversity of plants and animals. The average temperatures in this region remain high with warm summer. It remains frost free. The soil is nutrient deficient. Due to hot temperature the rate of transpiration remains high as a result the concentration of the water vapors remain high. This is responsible for increasing the humidity in the atmosphere also this region receives appreciable amount of rainfall annually. The average rainfall range is 200-450 centimeters.
a)Hari drove for 2 hours at a speed of 60km/h and next3 hours at a speed of 70km/h. Calculatehis average speed for the whole journey.b)A police car drives with a constant speed of 70km/h. How long it will take to cover a distance of 135 km? Express the speed in m/s
Answer:
Remember the relation:
Speed*Time = Distance.
Then first let's find the total distance that Hari drove.
First, he droves 2 hours at 60km/h, then the total distance traveled is:
Distance = 2h*60km/h = 120km
Then he droves 3 hours at 70km/h
The distance here is:
Distance = 3*70km/h = 210km
The total distance traveled is 120km + 210km = 330km
The total time of the travel is 2 hours + 3 hours = 5 hours.
The average speed is calculated as:
Av speed = (total distance)/(total time)
Av speed = (330km)/(5 h) = 66km/h
The average speed is 66km/h.
b) We know that the speed is 70km/h, but we want to write this in m/s.
Then we first know that 1 km = 1000m
then:
1 = (1000m/1km)
Then 70km/h = 70 km/h*(1000m/1km) = (70*1000) m/h = 70,000 m/h
Now we know that 1h = 3600 seconds, then:
1 = (1h/3600s)
So we can write:
70,000 m/h = (70,000 m/h)* (1h/3600s) = 70,000/3600 m/s = 0.019 m/s
and the distance is 135 km
Again, we can rewrite this as:
135km = 135km*(1000m/1km) = 135,000m
Then we want to solve:
(0.019m/s)*time = 135,000 m
We want to solve this for the time, then we get:
time = (135,000m)/(0.019m/s) = 7,105,263.2 seconds = 1.93 hours
The microwaves produced inside a microwave have a wavelength of 12.0m and a frequency of 25Hz. At what speed do the microwaves travel in units of m/s ?
Answer: 300 m/s
Explanation:
The equation for finding wave speed is the wavelength times the frequency which would be
12.0mx 25hz=300m/s
If the Universe was born at the Big Bang, what existed before then?
Hey,
QUESTION)This is a complicated question that would be debated by many physicists. How to answer this question when we are struggling with the genesis of the universe? Many theories on the origin of the universe have been put forward, but the Bing Bang is probably, or at least to date, the most likely theory. If today the universe is expanding, some astronomers hypothesise that before the Bing Bang the universe already existed but that it was condensing, according to this hypothesis the Bing Bang would correspond to the limit point of compression of the universe.
But if we remain in the traditional theory the Bing Bang is at the origin of all the matter we know, as well as light. Before the Bing Bang, in other words before the universe, there was NOTHING.
label the sun. which layer of the sun is 1#?
Answer:
It is the core.
The light in a lighthouse revolves around an axis. The beam of light is perpendicular to the axis but the axis is not vertical. Because the axis is tilted, when the light beam points east it is inclined upward at 3 degree(s). When the beam points north, it is inclined upward at 10 degree(s). What is the maximum angle of elevation of the light beam
Answer:
22.8°
Explanation:
Given conditions:
When light beams to the east it is inclined at 3 degrees upwards
When the light beams points to the north it is inclined 10 degrees upwards
Determine the maximum angle of elevation of the light beam
let slope of the line ( m ) = tan ∅
In x-direction ( eastwards ) = df / dx = tan 3°
In y-direction ( north ) = df / dy = tan 10°
| νf | = | < tan 3° , tan 10° > |
therefore | νf | = [tex]\sqrt{(tan 3)^2 + (tan10)^2}[/tex]
| νf | = [tex]\sqrt{0.02032 +0.42037 }[/tex] = √ 0.44069 = 0.42037
hence the maximum angle of elevation = tan^-1 ( 0.42037 ) = 0.39794 rad
to degrees = 22.8°
The maximum angle of elevation of the light beam will be 22.8°. An elevation is its altitude beyond or below a specified reference point, It is calculated in degrees.
What is elevation?An elevation is its height above or below a fixed reference point, It is measured in degrees.
The given data in the problem is;
Angle inclined when light beams to the east = 3° upwards
Angle inclined light beams point to the north = 10° upwards
m is the slope of the line = tan ∅
The maximum angle of elevation of the light beam is found as;
The angle inclined in the x and y-direction;
In x-direction ( eastwards ) = df / dx = tan 3°
In y-direction ( north ) = df / dy = tan 10°
The resultant angle of both the above angle is;
[tex]\rm v_f = \sqrt{(tan3^0)^2 +(tan 10^0)^2 } \\\\ \rm v_f = \sqrt{(0.020320)^ +(0.42037) } \\\\ \rm v_f = \sqrt{0.44069 \\\\[/tex]
[tex]\rm v_f = 0.42037[/tex]
[tex]\rm \theta= tan^-1 (v_f) \\\\ \rm \theta= tan^-1 (0.42037) \\\\ \rm \theta= 22.8 ^0[/tex]
Hence the maximum angle of elevation of the light beam will be 22.8°.
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You hold your physics textbook in your hand. (Assume that no other objects are in contact with the book.)
a. Identify the forces acting on the book.
1. book on hand
2. hand on book
3. floor on book
4. earth on book
b. For each force you identified in part (a), indicate the direction. (If a force is not applicable, choose NA.)
1, book on hand __________
2. hand on book __________
3. floor on book __________
4. earth on book _________
Answer:
a) Please see below as the answer is self-explanatory.
b) 1. vertically downward
2. vertically upward
3 N/A
4 vertically downward.
Explanation:
a)
If the book is hold by the hand, this means (according to Newton's third law) that both exert a force on each other, equal and opposite.In this case this pair is formed by normal forces, the normal force (upward) that the hand does on the book (avoiding it to be accelerated downward) and the normal force that the book does on the hand (downward) avoiding it to be accelerated in the upward direction.The other force that acts on the book is the one due to gravity, and is always downward, which is numerically equal to the normal force that the hand does on the book, due to the book is at rest. There is no interaction between the book and the floor, so there is no force between them, neglecting the gravitational attraction between their masses.I need help with both 3 and 4 please help?
PLEASE HELP ME WITH THIS ONE QUESTION
What is the final temperature when 625 grams of water at 75.0° C loses 7.96 x 10^4 J? (cwater = 4186 J/kg°C)
Answer:
T_f = 44.6 ° C
Explanation:
We can solve this exercise using the calorimetry relations
Q = m c_e ΔT
ΔT = [tex]\frac{Q}{m \ c_e}[/tex]
let's calculate
ΔT = -7.96 10⁴ /(0.625 4186)
ΔT = -3.04 10¹
The negative sign indicates that the temperature decreases
the temperature variation is
T_f - T₀ = ΔT
T_f = T₀ + ΔT
T_f = 75.0 - 30.4
T_f = 44.6 ° C
True or false—If a rock is thrown into the air, the increase in the height would increase the rock’s kinetic energy, and then the increase in the velocity as it falls to the ground would increase its potential energy.
If a rock is thrown into the air, the increase in the height would increase the rock’s kinetic energy, and then the increase in the velocity as it falls to the ground would increase its potential energy. _ This is false statement.
What is projectile motion?When a particle is hurled obliquely near the surface of the earth, it travels along a curved path while accelerating continuously in the direction of the planet's center (we assume the particle stays close to the surface of the globe). Such a particle's motion is known as projectile motion, and its route is referred to as a projectile.
In projectile motion total energy is conserved. Hence, when a rock is thrown into the air, the increase in the height would increase the rock’s potential energy, and then the increase in the velocity as it falls to the ground would increase its kinetic energy.
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An elevator motor in a high-rise building can do 3500 kJ of work in 5 min. Find the power developed by the motor. Explain if you can plz
Answer:
P = 11666.6 W
Explanation:
Given that,
Work done by the motor, W = 3500 kJ
Time, t = 5 min = 300 s
We need to find the power developed by the motor. Power developed is given by :
[tex]P=\dfrac{E}{t}\\\\P=\dfrac{3500\times 10^3}{300}\\\\P=11666.7\ W[/tex]
So, the required power is 11666.6 W.
Jorge wants to know if yearly income and amount of tax returns are related in any way. In looking for an association between
these two variables, Jorge should utilize the method of research.
a. Correlational
b. Ethnographer
c. Naturalistic observation
d. Case study
We have that In looking for an association between these two variables, Jorge should utilize the
Correlational Research
This a research method that focuses on two variant variable and uses statistics to analyse the to achieve desired result
From The options we have that
a Correlational Research
This a research method that focuses on two variant variable and uses statistics to analyse the to achieve desired result
b. Ethnographer Research
This is simply the a Research method that focuses on variable mostly people in the Natural habitat and studies them or conversations with them for best results
c. Naturalistic observation Research
This method of research focuses on people in the Natural environment to determine their mental State .It is use mostly by Psychologists
d. Case study Research
This is is the use of real life testimonies to develop results to a particular Research it entails the study of Past events.
In conclusion the different variables
Having understood the different methods
In looking for an association between these two variables, Jorge should utilize the
Correlational Research
This a research method that focuses on two variant variable and uses statistics to analyse the to achieve desired result
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1. Which statement best describes the cycle of water through the human body?
A Water is taken into the body through transpiration and released through perspiration.
B Water is taken into the body through ingestion and released through perspiration.
C Water is cycled through the body through the process of transpiration.
D Water is taken into the body through perspiration and released through transpiration.
Answer:
I would say B
Explanation:
the other ones don't seem right
Which of these describes static electricity?
a temporary charge
a steady charge
plssssssssssssssss answer not in a meen way but correct answers only plssssssssssssssssssssssssssssssssssssssssssssssss answer correctly i will drop a thx and give you brainlest and rate your answer 5 stars if you are correct
a temporary charge is the right answer
