Answers
Answer:
Explanation:
initial velocity u = 54 km/h = 15 m/s
final velocity v = 18 km/h = 5 m/s
distance s = 10 m
1. v^2 = u^2 + 2as
5^2 = 15^2 + 2a × 10
25 = 225 + 20a
25 - 225 = 20a
20 a = -200
a = -200/2
a = -100m/s^2
∴Deacceleration = -100m/s^2
2. v = u + at
5 = 15 -100t
5-15 = -100t
-10 = -100t
t = 100 / 10
∴t = 10 sec
Total distance covered by the car 10 m
To me, the hardest part of this whole thing is keeping the units straight. We're starting out with information given to us in kilometers, hours, and meters, and we have to come up with answers in m/s² , seconds, and meters.
When I worked this problem, I jumped right in without thinking, and I immediately got bogged down when I had to go off to the side and convert some units.
Now I know better. THIS time, before we get all tangled up trying to solve anything, let's get clever and change everything to m/s right now !
(54 km/hour) · (1,000m/km) · (1 hour/3600 sec) = 15 meters/second
(18 km/hour) · (1,000 m/km) · (1 hour/3600 sec) = 5 meters/second
NOW I'll betcha it's gonna be about 70% faster and easier !
i). Acceleration = (change in speed / time for the change)
We know the distance, but not the time. I know there's a formula for it, but I've learned so many formulas during my lifetime that I can't remember ALL of them. So I just memorize some of them, and I work things out from the formulas that I know. Here's how I do time:)
Average speed during the given slow-down = (1/2)·(15+5) = 10 m/s
Distance covered during the given slow-down = 10 m.
Time = (distance) / (average speed) = (10m) / (10 m/s) = 1 second
Acceleration = (change in speed) / (time for the change)
Acceleration = (5 m/s - 15 m/s) / (1 second)
Acceleration = (-10 m/s) / (1 second)
Acceleration = -10 m/s² (or 'Deceleration' = 10 m/s² )
_____________________________________________
For parts ii). and iii)., there's a big shift in the question.
It only gave you the slow-down from 54 to 18 km/hr for the purpose of calculating the deceleration. NOW, for the rest of the answers, it's talking about a complete stop ... 0 m/s .
____________________________________________
ii). Time required to stop = (initial speed) / (deceleration)
Time to stop from 54 km/hr = (15 m/s) / (10 m/s²)
Time to stop = 1.5 seconds
iii). Distance covered = (average speed) · (time to stop)
Distance covered = (7.5 m/s) · (1.5 sec)
Distance covered = 11.25 meters
OR ... use the official formula:
Distance = (1/2) · (acceleration) · (time² )
Distance = (1/2) · (10 m/s²) · (1.5 sec)²
Distance = 11.25 meters yay !
Related Questions
which type of bond is found between the atoms of a molecule?
Answers
Answer:
Covalent Bond is found between the atoms of a molecule.
a boy runs from his house to school at speed 5m/s on a straight road and returns with speed of 10m/s.The distance between the house and school is 100m. Find his average velocity.... with explaination please
Answers
Explanation:
time spent to run from house to school=100/5=20s
time spent to return from school=100/10=10s
average velocity=200m/(10+20)
=6.66m/sA 17-tooth spur pinion has a diametral pitch of 8 teeth/in, runs at 1016 rev/min, and drives a gear at a speed of 508 rev/min. Find the number of teeth on the gear and the theoretical center-to-center distance.
Answers
9. [03.03]
When comparing two circuits, you note that circuit one has twice the voltage and half the resistance of circuit two.
Answers
Answer:
Circuit one will have more current than circuit two
Explanation:
I am assuming that you have to see which circuit has the greater current in this case. Well, this is the perfect example of Ohm's Law, which states the following -
V = IR,
where V = voltage / potential difference, I = current, and R = resistance
If one circuit has twice the voltage and half the resistance of the second circuit, as voltage is directly proportional to the resistance -
2V = I( 1 / 2R ),
4V = IR,
I = 4V / R
Whereas in the second circuit -
V = IR,
I = V / R
As you can note, voltage is directly proportional to the current ( I ) as well as the resistance. The only difference between the two formulas I = 4V / R, and I = V / R is the difference in the voltage. With the voltage being 4 times greater in the first circuit, and current is 4 times greater in the first circuit as well.
Hence, circuit one will have more current than circuit two
That's a very interesting observation. When you notice that, does it stimulate any questions in your mind due to your natural curiosity ?
For example, do you walk away wondering, perhaps, how the current in the two circuits might compare ? If so, you've come to the right place. Read on:
Take the form of Ohm's Law for current . . . I = V / R . . . and apply it to both circuits:
For the second circuit: I₂ = V / R
For the first circuit:
I₁ = (2V) / (R/2)
Multiply numerator and denominator by 2 :
I₁ = (4V) / R
I₁ = 4 (V / R)
I₁ = 4 I₂
A body oscillates with 25hz what is its time period
Answers
Answer:
4 seconds
Explanation:
The frequency of a body is the number of oscillations in one second. It is the number of cycles per unit time. The S.I unit of frequency is the Hertz (Hz).
The period of a body is the time taken to complete one oscillation. The period is inversely proportional to the frequency of the body. It is the reciprocal of frequency and the S.I unit is second (s).
A body oscillates with 25hz. Therefore the frequency (f) = 25 Hz.
The period (T) is given as:
[tex]Period (T)=\frac{1}{frequency(f)} \\T=\frac{1}{f} =\frac{1}{0.25}=4\\T=4\ seconds[/tex]
I NEED HELP PLEASE, THANKS! :)
The electric field around a positive charge is shown in the diagram. Describe the nature of these lines.
Answers
Answer:
They move outwards.
They don't intersect each other at any point.
They show the electric field.
Explanation:
Answer:
Please read the answer below
Explanation:
the nature of these lines refers to the fact that positive charges generate field lines that are directed out of the positive charges, and in turn are directed towards some negative charge present somewhere in the universe.
By consensus, the electric field lines leave the positive charges and enter the negative charges. That is the reason why in a scheme like the shown in the image, is considered implicitly the existence of a negative charge, in some place of the universe.
A ball moving at a velocity of 10 meters/second has a momentum of 8.0 kilogram meters/second. What is its mass?
Answers
Answer:
0.8 kilogram
Explanation:
Mass:This can be defined as the quantity of matter a body contained. The S.I unit of mass if kg.
From the question,
M = mv................. Equation 1
Where M = momentum, m = mass. V = velocity
make m the subject of the equation
m = M/v.............. Equation 2
Given: M = 8.0 kilogram meters/second, v = 10 meters/second
Substitute these values into equation 2
m = 8.0/10
m = 0.8 kilogram
Which of these statements describes a constraint imposed on scientific
researchers by the Antarctic Treaty System?
A. The safety of scientists is ensured.
B. Facilities are inspected for compliance.
c. Some areas are protected from human activity.
D. Scientific knowledge is not shared.
Answers
Answer:
The answer is C.
why decomposition of sugar on heating is an irreversible change.
Answers
Answer:
The heat of formation of the products of the heating of sugar, which is caramel is higher and due to the new complexes formed such there is increased change in free energy between the products and the reactants of the sucrose decomposition by heating, making the reaction is irreversible
Explanation:
Sugar, also known as sucrose, C₁₂H₂₂O₁₁, is a disaccharide made up two monosaccharides, fructose, C₆H₁₂O₆, and glucose, C₆H₁₂O₆ joined together by a glycosidic covalent bond as such the molecule of sugar has one less molecule of H₂O than the fructose and the glucose it is made of which on heating the sugar the glycosidic bonds break and due to deficiency in the amount of H₂O the fructose and glucose combine with themselves to form caramel which has a much lower hydrogen and oxygen proportion such as C₂₄H₂₆O₁₃, which is darker and contains free radicals making caramel sticky.
Therefore, the heat of formation of the caramel is higher and due to the formation of the complexes there is increased change in free energy between the products than the reactants of the decomposition of sugar by heating, therefore, the reaction is irreversible.
HELP NEEDE ASAP!!!!!!!! How do you understand by the longitudinal wave? Describe the longitudinal nature of sound waves
Answers
Answer:
Sound as a Longitudinal Wave
For a sound wave traveling through air, the vibrations of the particles are best described as longitudinal. Longitudinal waves are waves in which the motion of the individual particles of the medium is in a direction that is parallel to the direction of energy transport.
Answer:
Hey!
Here is your answer!
Explanation:
LONGITUDINAL WAVES:
These are waves where the transferral of energy is PARALLEL to the direction it travels in...For Example...Sound Waves are Longitudinal as they move in a series of COMPRESSIONS and RAREFACTIONS (typical of all Longitudinal Waves)...
The compressions are known in diagrams to be an area of a dense collection of PARTICLES where the energy (or sound in this case) is being transferred in the same direction as the movement...
The rarefactions are shown as almost empty area of particles where the medium (the matter of which the wave travels in) is moving...
Hope this helps!
*here's a diagram*
An airplane starts at rest and accelerates down the runway for 25 s. At the end of the runway, its final velocity is 75 m/s east. What is its acceleration?
Answers
Answer
3m/s²
Explanation
u=o
t=25s
v=75m/s
from Newton's first law of motion,
v=u+at
75=0+a(25)
75=25a
a= 75/25
a=3m/s²
The acceleration of the airplane is 3m/s².
What is acceleration?Acceleration is rate of change of velocity with time. Due to having both direction and magnitude, it is a vector quantity. Si unit of acceleration is meter/second² (m/s²).
Given parameters:
Initial velocity of the airplane: u=o.
Time taken: t=25s.
Final velocity of the airplane: v=75m/s.
We have to find acceleration of the plane: a = ?
We know that for accelerating motion of the air plane; final velocity can be expressed as:
v=u+at
⇒ 75=0+a(25)
⇒ 75=25a
⇒ a= 75/25
⇒ a= 3m/s².
hence, acceleration of the airplane is 3m/s².
Learn more about acceleration here:
brainly.com/question/12550364
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The kicker now kicks the ball with the same speed as in the number of 4,but at 60.0°from the horizontal or 30.0° from the vertical. a.What is the time the ball is in the air? b.What is the distance the balls travel before it hits the ground? c.What is the maximum height?
Answers
Answer:
Explanation:
1) The time of flight equation for projectile motion can be used here to find total time in air.
t = 2vsin∅ / g
where v is speed, Ф is launch angle
t = 2×4×sin 60 / 9.8
t = 0.71 seconds
2) Distance where it hit the ground is called as range and has the following standard equation
D = v² sin2Ф/g
D = 4²sin 2×60 / 9.8
D = 1.41m
3) Maximum elevation is maximum time reached
h = v² sin²Ф / 2g
h = 4²sin² 60 / 2*9.8
h = 0.61 m
Show that a light ray that strikes two mutually perpendicular reflecting surfaces is reflected back exactly parallel to the direction from which it came.
Answers
Take a look at the attachment below. As you can see, the figure demonstrates a 90 degree angle such that the surfaces are perpendicular, and hence are independent of the angle of incidence. You could say that this forms a part of a parallelogram -
What is torque in physics ?
Answers
Answer:
Torque is a measure of the force that can cause an object to rotate about an axis.
Answer:
Torque is a measure of how a force acting on an object causes that object to rotate.
Why does time slow down the closer you get to a black hole, I know that time slows down the faster you move through space and the closer you get to the speed of light, but how does being near a black hole slow time down even futher?
Answers
Answer:
Near the black hole, The gravitational pull is so strong and the black hole has a lot of stress energy. This causes the clock to tick slower than usual and due to this , Time slows down to a great extent.
if the input force on a wheel and axle is 2 N and the output force is 20N what is its mechanical advantage
Answers
Mechanical Advantage is always (Output Force) / (Input Force) .
MA = (20 N) / (2 N)
MA = 10
Does the earths magnetic field change with time?
Answers
Answer:
As per the fossil fuel records, magnetic field reversal does not impact living beings. It will take almost a century for the poles to complete the shift. Meanwhile, the earth is left with almost zero magnetic field.
Using the letters for the seven colours and starting with R (Red), what is the correct order for the colours in a rainbow? Your answer should be in the form RXXXXXX Which of these seven colours has the shortest wavelength?
Answers
Answer:
Red
Orange
Yellow
Green
Blue
Indigo
Violet
shortest wavelength: violet (380 nanometers)
¯\(°_o)/¯
Answer:
Red Orange Yellow Green Blue Indigo Violet
violet has the shortest wavelength
happy to help :)
In which direction of the wave motion do longitudinal waves transfer energy?
A-perpendicular
B- parallel
C- close
D-equal
Answers
Answer:
B, Parallel.
Explanation:
Mark as brainliest pls!
The wave motion does longitudinal waves transfer energy in the direction Parallel to the wave motion. Hence, option B is correct.
What is a Wave?Waves are disturbances that move regularly and orderly from one location to another. Although sound, lighting, and the movement of elementary particles all have wave-like characteristics, surface waves that move on water are the most well-known.
The disturbance periodically oscillates with a set frequency and wavelength in the simplest waves (see periodic motion). In contrast to electromagnetic waves, which do not require a medium to travel and may move through a vacuum, mechanical waves, like sound, need a medium to go through. A medium's characteristics determine how a wave will travel across it. Seismic wave is also seen.
Therefore, option B is correct.
To know more about Wave:
https://brainly.com/question/3639648
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what is called gratational force
Answers
Answer:
Gravitational force can be seen as the pull that the earth has on an piece of matter. Everything on earth has a force acting on it which is gravity. It tries to pull two object closer to each other but never apart. The numerical value for gravitational force is 9.8 m/s^2 for free falling objects
Explain the concept of "charge" and how it relates to electricity?
Answers
Answer:
An Electric "charge" is a property of matter that causes a force to repel or attract when placed into a magnetic field. These charges can be replicated into positive and negative electrons when made from a chemical reaction.
Answer:
an electri
Explanation:
Modifiable strength improvement factors include all of the following except...??
Answers
Answer:
Muscle size and training specifiicty
Explanation:
It depends on all other factors such as anatomy and psychology, muscle fiber recruitment, motor pattern development and muscle memory but to increase modifiable strength, size plays no big role.
Infrared waves have higher frequencies than microwaves. Which statement best compares the energy of these two types of waves?
Answers
Each infrared photon carries more energy than any microwave photon.
(If this statement is not one of the choices, then it's really sad that you couldn't show us the list of choices to select from.)
Answer:
The energy of infrared waves is more than that of microwaves.
Explanation: Just completed on Edmentum
La física moderna se encarga del estudio de: a) Las interacciones que conducen a un cambio de movimiento b) Los fenómenos luminosos considerando a la luz como un movimiento ondulatorio electromagnético c) Las interacciones debidas a cargas eléctricas d) Los comportamientos de las partículas que forman la materia y las fuerzas que las rigen
Answers
Answer:
corrct are a and d
Explanation:
La denominada Física moderna se desarrollo a principios del siglo XX, en respuesta a la imposibilidad de la física clásica de Newton de explicar una serie de fenómenos.
En es física moderna se desarrollo un modelos para explicar el movimiento de los cuerpo que toma como base que la velocidad máxima de un cuerpo es la velocidad de la luz en el vació, esta parte es denominada relatividad especial.
En consecuencia la afirmación correcta es a
En un segunda partee la fiscal moderna se desarrollo un explicablemente intercalación de las partículas que forman la materia ( átomos) y la fuerzas (potenciales ) con que interactúan, esta segunda parte se denomina Mecánica cuántica.
Por lo cual la otra respuesta correcta es la d
Traslate
The so-called modern physics was developed at the beginning of the 20th century, in response to the impossibility of Newton's classical physics to explain a series of phenomena.
In modern physics, a model was developed to explain the movement of the body based on the fact that the maximum speed of a body is the speed of light in vacuum, this part is called special relativity.
Consequently the correct statement is to
In a second part of the modern prosecutor, an explanatory intercalation of the particles that make up matter (atoms) and the (potential) forces with which they interact is developed, this second part is called Quantum Mechanics.
So the other correct answer is d
Un proyectil es lanzado horizontalmente desde una altura de 12 metro con una velocidad de 80 m/sg. a.Calcular el tiempo de vuelo b. Su alcance horizontal y velocidad de impacto contra el suelo.
Answers
Answer:
t= 1,56 s , x= 124,8 m , v = (80 i^ - 15,288 j ) m/s
Explanation:
Este es un ejercicio de lanzamiento proyectiles, comencemos por encontrar el tiempo que tarda en llegar al piso
y = y₀ + [tex]v_{oy}[/tex] t – ½ g t²
en este caso la altura inicial es y₀= 12 m y llega a y=0 , como es lanzado horizontalmente la velocidad vertical es cero (v_{oy}=0)
0 = y₀ – ½ g t²
t= √ (2 y₀/g)
calculemos
t= √ ( 2 12 / 9,8)
t= 1,56 s
El alcance del proyectil es la distancia horizontal recorrida
x = v₀ₓ t
x = 80 1,56
x= 124,8 m
La velocidad de impacto cuando toca el suelo
vx = v₀ₓ = 80 ms
[tex]v_{y}[/tex] = v_{oy} – gt
v_{y} = - 9,8 1,56
v_{y} = - 15,288 m/s
la velocidad es
v = (80 i^ - 15,288 j ) m/s
Traducttion
This is a projectile launching exercise, let's start by finding the time it takes to reach the ground
y = y₀ + v_{oy} t - ½ g t²
in this case the initial height is i = 12 m and it reaches y = 0, as it is thrown horizontally the vertical speed is zero ([tex]v_{oy}[/tex] = 0)
0 =y₀I - ½ g t²
t = √ (2y₀ / g)
let's calculate
t = √ (2 12 / 9.8)
t = 1.56 s
Projectile range is the horizontal distance traveled
x = v₀ₓ t
x = 80 1.56
x = 124.8 m
Impact speed when it hits the ground
vₓ = v₀ₓ = 80 ms
v_{y} = v_{oy} - gt
v_{y} = - 9.8 1.56
v_{y} = - 15,288 m / s
the speed is
v = (80 i ^ - 15,288 j) m / s
The cartoon of the roadrunner and the coyote usually has rockets going at around 8 kilometers per minute. How much is this in miles per hour? (1m = .00062 miles)If we have a terrain with a square house in the middle, the walls of the square house are 50.0 yards long and has 10 yards high ceilings. What is the volume of the interior of the house in cubic meters and cubic centimeters? (1 yard = 3 feet, 1 meter = 3.28 foot)The acceleration of an object is given by 314,000 Hectometers per hour squared. Convert the units to Meter per second square and miles per second square.
Answers
Answer:
1 feet
Explanation:
1 feet = 1 feet so its one feet
taking a rest one or two days in between training sessions helps your body blank much faster
Answers
Answer:
Recover
Explanation:
Got it right on the quiz
the weight of a body will be zero during free fall. Why?
Answers
Answer:
The apparent weight of a freely falling body is zero. When a body falls freely, it is falling with an acceleration =g. Thus the entire gravitational force acting on it is utilized in accelerating it and hence its weight is not felt.
The volume of a piece of metal of a mass 6 gram is 15cm3. What is the density of the metal piece?
Answers
Answer:
0.4 g/cm^3
Explanation:
The density of an object can be found using the following formula.
d= m/v
where m is the mass and v is the volume.
The mass of the metal is 6 grams and the volume is 15 centimeters^3
m=6 g
v= 15 cm^3
Substitute these into the formula.
d= 6 g/ 15 cm^3
Divide 6 g by 15 cm^3 (6/15=0.4)
d= 0.4 g/ cm^3
The density of the metal is 0.4 grams per cubic centimeter.
Density = (mass) / (volume)
Density = (6 g) / (15 cm³)
Density = (6/15) (g/cm³)
Density = 0.4 g/cm³
This 'metal' has less than half the density of water, and it floats on water ! It cannot be of Earthly origin, and must have been dropped here by aliens.
Either that, or else the metal has been hammered and stretched and beaten out and shaped so that it has an artificially large volume ... something like the way sailing ships are made out of thick plates of steel.
give two disadvantage of hydroelectric power
Answers
Explanation:
damming of water which changes water flow, in turn could/does cause road/ property flooding
directly being related to water usage, if we have droughts(lack of rain) there we have less water to use for the power.
Environmental consequences
Limited Reservoirs