Answer:
2.5 s
Explanation:
The formula for acceleration is ;
a= v₂-v₁ / t
where ;
a= acceleration = -2 m/s²
v₂= final velocity = 10 m/s
v₁ = initial velocity = 15 m/s
t= time taken for the car to accelerate = ?
Applying the values in the formula as;
a= v₂-v₁ / t
-2 = 10 - 15 / t
-2t = -5
t= -5/ -2
t= 5/2 = 2.5 s
Una curva de radio R = 75 [m] tiene un peralte hecho de tal forma que un auto andando a v1 = 35 [m/s] no derrape incluso con el piso congelado (sin roce). ¿Cuál es el coeficiente de roce estático mínimo necesario entre las ruedas y el pavimento para que, en un día seco y soleado, el auto no derrape cuando avanza a v2 = 118 [m/s]?
Answer:
053.
Explanation:
Given that the radius of curvature of the path, R = 75 m.
Speed of the car on that path , [tex]v_1 = 35 m/s[/tex]
The centripetal force,[tex]F_c[/tex] acting on the body having mass, m, when it moves with the velocity v on curved path having radiusR
Ris[tex]F_c = mv^2/R[/tex]
Gravitational force, [tex]F_g[/tex] = mg.
Let tha angle of superelevation is [tex]\theta.[/tex]
As the car does not skid even with zero friction, so
[tex]mg\sin\theta = (mv_1^2)/2 \cos\theta[/tex]
[tex]\Rightarrow \tan\theta = v_1^2/2g=\cdots(i)[/tex]
On sunny day, let the minimun static friction coefficient between the wheels and the pavement is [tex]\mu.[/tex]
As [tex]v_2[/tex] = 118 m/s is greater than v_so the car tends to skid in upper direction and the frictional
force,f, will acts is downward direction.
As there is no skidding, so
[tex]f+ mg\sin\theta= (m(v_2)^2)/R\cos\theta[/tex]
[tex]\Rightarrow f=(m(v_2)^2)/R\cos\theta - mg\sin\theta[/tex]
where [tex]f= \mu N.[/tex]
[tex]So, \mu = \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{N} \cdots(ii)[/tex]
Where N is the normal reaction can be determined by balancing the force in perpendicular direction of the plane.
[tex]N= mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta[/tex]
From equation (ii)
[tex]\mu = \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta}[/tex]
[tex]=\frac{-g\tan\theta+v^2/R}{v_2^2\tan\theta+g}[/tex]
[tex]= \frac {(m(v_2)^2)/R\cos\theta - mg\sin\theta}{mg\cos\theta+\frac {m(v_2)^2}{R}\sin\theta}[/tex]
[tex]=\frac{-g(v_1^2/2g)+v^2/R}{v_2^2(v_1^2/2g)+g}[/tex]
[tex]= \frac{v_2^2/R-v_1^2/R}{g+v_2^2/R\times v_1^2/Rg}[/tex]
[tex]=\frac{118^2/75-35^2/75}{9.81+118^2/75\times 35^2/(75\times 9.81)}[/tex]
=0.53
Hence, the minimum coefficient of friction is 0.53.
What does the triangle mean in physics?
In physics, the triangle symbol (∆) typically represents a change or difference in a particular quantity.
A triangle is often used to denote the difference between two values of a variable. For example, if we have two values of time, t1 and t2, the change or difference in time can be represented as Δt = t2 - t1, where Δt is the triangle symbol indicating the change in time. Similarly, it can be used to represent differences in other physical quantities such as displacement (∆x), velocity (∆v), or temperature (∆T). The triangle symbol (∆) is a shorthand notation commonly used in physics to indicate changes or differences.
In terms of change in displacement, the triangle symbol (∆) represents the difference between two positions or locations. It indicates the change in the object's position from an initial point to a final point.
For example, if an object initially starts at position x1 and then moves to position x2, the change in displacement (∆x) can be calculated as ∆x = x2 - x1. Here, ∆x represents the difference or change in the object's displacement.
The magnitude of ∆x gives the overall distance traveled by the object, and its sign indicates the direction of the displacement. A positive ∆x signifies a displacement in the positive direction (e.g., to the right or upward), while a negative ∆x represents a displacement in the negative direction (e.g., to the left or downward).
Therefore, The triangle symbol (∆) is commonly used in physics equations to denote changes or differences in various quantities, including displacement, velocity, time, and more. It helps us analyze and quantify the differences between two values of a physical quantity.
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Acceleration measures how much the ___________ of an object changes over time.
a) velocity
b) location
Answer: velocity
Explanation: v/t
if a truck goes 30 kilometers in 30 minutes what is the average speed
Answer:
60 km per hour
Explanation:
if you drive for 30 min and go 30km then if you drive for 60 min(1hr) then you would have driven 60km.
Answer:
60
Explanation:
hope this helps
1. A ball is thrown straight up.if the launch velocity is 15 m/s, at what velocity will the ball return to the thrower's hand?
2. A boat moves across a river going 18 m/s. At the same time there is a current flowing at a right angle to the boat at 6 m/s. What is the resulting velocity of the boat?
Answer:
1) The velocity of the ball return to the thrower's hand is -15 meters per second.
2) The resulting velocity of the boat is [tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex].
Explanation:
1) Let suppose that ball experiments a free fall, that is an uniform accelerated motion, in which effects from gravity and Earth's rotation can be neglected. The velocity of the ball is represented by the following equations of motion:
Position
[tex]v_{o}\cdot t -\frac{1}{2}\cdot g\cdot t^{2} = 0[/tex]
[tex]t\cdot \left(v_{o}-\frac{1}{2}\cdot g\cdot t \right) = 0[/tex] (1)
Velocity
[tex]v = v_{o}-g\cdot t[/tex] (2)
Where:
[tex]t[/tex] - Time, measured in seconds.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]v_{o}[/tex] - Initial velocity of the ball, measured in meters per second.
[tex]v[/tex] - Final velocity of the ball, measured in meters per second.
From (1), we get the time when the ball returns to the thrower's hand:
[tex]v_{o}-\frac{1}{2}\cdot g\cdot t = 0[/tex]
[tex]t = \frac{2\cdot v_{o}}{g}[/tex]
And then we apply this result in (2):
[tex]v = v_{o}-g\cdot \left(\frac{2\cdot v_{o}}{g} \right)[/tex]
[tex]v = -v_{o}[/tex] (3)
Then, the velocity of the ball return to the thrower's hand is -15 meters per second.
2) The resulting velocity of the boat ([tex]\vec v_{B}[/tex]) is represented by the vectorial sum of the velocity of the boat relative to the river ([tex]\vec v_{B/R}[/tex]) and the velocity of the river ([tex]\vec v_{R}[/tex]), both measured in meters per second, that is:
[tex]\vec v_{B} = \vec v_{R}+\vec {v}_{B/R}[/tex] (4)
If we know that [tex]\vec v_{R} = 6\,\hat{i}\,\left[\frac{m}{s} \right][/tex] and [tex]\vec v_{B/R} = 18\,\hat{j}\,\left[\frac{m}{s} \right][/tex], then the resulting velocity of the boat is:
[tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex]
The resulting velocity of the boat is [tex]\vec v_{B} = 6\,\hat{i}+18\,\hat{j}\,\left[\frac{m}{s} \right][/tex].
In a lacrosse game a ball is thrown with a force of 2000 N. The throwing force acted for 0.8
seconds. If the ball had a change in velocity, Av, of 50 m/s, what is the mass of the ball?
Answer:
Mass, m = 32 kg
Explanation:
Given that,
Force, F = 2000 N
The change in velocity, (v-u) = 50 m/s
Time, t = 0.8 s
We need to find the mass of the ball. The net force acting on an object is given by :
F = ma
Where a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\m=\dfrac{Ft}{(v-u)}\\\\m=\dfrac{2000\times 0.8}{50}\\\\m=32\ kg[/tex]
So, the mass of the ball is 32 kg.
A ball is dropped from a height of 50 meters above the ground. What is its velocity the moment it hits the ground?
Answer:
The distance is 45m. (s)
Acceleration is 9.8 m/s^2 (acceleration due to gravity). (a)
We have to find the time (t)
By the 3rd equation of motion,
s = ut + 1/2 at^2 (here u is the initial velocity of the ball)
Since the initial velocity was 0 m/s, the formula becomes s = 1/2 at^2.
(substituting the values in the formula)
45 = 1/2 x 9.8 x t^2
45 = 9.8/2 x t^2
45 = 4.9 x t^2 (9.8/2 = 4.9)
(divide 4.9 on both sides)
45/4.9 = 4.9 x t^2 / 4.9
9.1836 = t^2
3.030 = t
So it takes approximately 3 seconds for the ball to reach the surface of the earth (neglecting air resistance). You can try the same with 50 m .
The velocity of the ball the moment it hits the ground is equal to 31.3 m/s.
What is the equation of motion?Equation of motion has established a relation between the velocity of the body and acceleration of the body when the body is moving with uniform acceleration along a straight line. The distance traveled in a specific time has expressed a set of equations termed equations of motion.
The first equation of motion can be expressed as follows:
v = u + at
The second equation of motion can be expressed as follows:
S= ut + (1/2)at²
Where u is the initial velocity of a body, v is the final velocity, S is the distance, a is the acceleration and t is the time.
Given, the distance traveled by the ball, S = 50 m
and, the initial velocity of the ball, u = 0 as ball is at rest initially.
From the second equation of motion, find the value of 't':
50 = (0) t + (1/2)× (9.8) ×(t²)
t = 3.19 sec
Now from the first equation of motion, find the value of the final velocity of the ball:
v = (0) + (9.8) (3.19)
v = 31.3 m/s
Therefore, the ball hits the ground with a velocity of 31/3 m/s.
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A car is driving down the road at 35 m/s when the driver slams on the brakes. The car stops in a distance of 75 meters. The braking force necessary to do this is 9,800 Newtons. How much work do the brakes perform stopping the car?
Answer:
If the car is initially travelling at u m/s, then the stopping distance d m travelled by ... the speed of the car at the instant the brakes are applied. ... Common usage will force us to depart from this later in the notes. ... The history of these equations is not absolutely clear, but we do have some ... Newton (1642–1727) and Leibniz.
Explanation:
hope this helped
The photo shows two yeast cells. Each cell is an individual organism. Which sentence best describes what happened to each cell during cell growth?
A. It will become many different cells.
B. It will produce offspring with a mate.
C. It will divide in half to form two new cells.
D. It will become larger by taking in nutrients.
The answer is option c - It will divide in half to form two new cells..
Explanation:
The sentence that best describes what happened during cell growth is ;
( D ) It will become larger by taking in nutrients
As the yeast cells begin to grow ( i.e. cell growth ), they will require more nutrients and as they take in the necessary nutrients they will gradually increase in size ( becoming larger ) which is a vital sign of cell growth and development, which will be seen in the yeast cells as they undergo cell growth.
The production of offsprings with a mate does not describe an activity that occurs in cell growth.
Hence we can conclude that The sentence that best describes what happened during cell growth is, It will become larger by taking in nutrients.
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My Lou Vee Air Car's propeller rotates, but it does not move the car forward. Can someone please help?? This is due on Monday!
Answer:
The force to get the plane moving, and to balance the friction so it does not stop, is provided by the propeller. However, the wheels provide the acceleration of the car.
Explanation:
Anyone play Among US?
Answer:
Yes
Explanation:
Its a good game.
Answer:
oof
Explanation:
Melissa my pet cow from childhood that i could ride like a horse had a weight of 0.65 tons. Philip my pet rabbit had a weight of 192 ounces. How many philips would it take to weigh as much as one melissa
Answer:
11 times the weight of Philip.
Explanation:
From the question given above, the following data were obtained:
Weight of Melissa (i.e cow) = 0.65 tons
Weight of Philip (i.e rabbit) = 192 ounces
Next, we shall express the weight of Philip (i.e the rabbit) in tons. This can be obtained as follow:
1 ounce = 3.125×10¯⁵ ton
Therefore,
192 ounce = 192 ounce × 3.125×10¯⁵ ton / 1 ounce
192 ounce = 0.06 ton
Thus, the weight of Philip (i.e the rabbit) in ton is 0.06 ton.
Next, we shall determine the ratio of the weight of Melissa (i.e the cow) to the weight of Philip (i.e the rabbit). This can be obtained as follow:
Weight of Melissa (i.e cow) = 0.65 ton
Weight of Philip (i.e rabbit) = 0.06 ton
Melissa /Philip = 0.65/0.06
Melissa /Philip = 11
Melissa = 11 × Phillip
Thus, it will take 11 times the weight of Philip to weigh as much as Melissa.
A roller coaster with a potential energy of 235,200 J sits at the top of a 30 m high hill. What is the mass of the roller
coaster? (Formula: PE = mgh)
O 800 kg
O 7,840 kg
O 8,000 kg
O 78,400 kg
Answer:
800 kg
Explanation:
I just did it :)
A motorcyclist sees a branch in the road and hits the brakes, slowing down at -6.42 m/s. if it takes him 2.85 seconds to stop, what was his starting velocity?
Use the definition of average acceleration:
a = ∆v / t
If v is the starting speed, then ∆v = 0 - v, so solve for v :
-6.42 m/s² = (0 - v) / (2.85 s)
v = (6.42 m/s²) (2.85 s)
v ≈ 18.3 m/s
If a rock is dropped from the top of a tower at the front of it and takes 3.6 seconds to hit the ground. Calculate the final velocity of the penny in m/s. What is the height of the tower?
Answer:
35.28m/s; 63.50m
Explanation:
Given the following data;
Time, t = 3.6 secs
Since it's a free fall, acceleration due to gravity = 9.8m/s²
Initial velocity, u = 0
To find the final velocity, we would use the first equation of motion;
[tex] V = u + at[/tex]
Substituting into the equation, we have;
[tex] V = 0 + 9.8 * 3.6[/tex]
V = 35.28m/s
Therefore, the final velocity of the penny is 35.28m/s.
To find the height, we would use the second equation of motion;
[tex] S = ut + \frac {1}{2}at^{2}[/tex]
Substituting the values into the equation;
[tex] S = 0(3.6) + \frac {1}{2}*9.8*(3.6)^{2}[/tex]
[tex] S = 0 + 4.9*12.86[/tex]
[tex] S = 0.5 *36[/tex]
S = 63.50m
Therefore, the height of the tower is 63.50m.
which is the smallest particle containing the same characteristics for a compound?
Answer:
A compound is a substance that consists of two or more elements in a unique composition. The smallest particle of a compound is called a molecule. Chemical bonds hold together the atoms of molecules
Un prisma rectangular de cobre, de base igual a 36 centímetros cuadrados y una altura de 10 cm se sumerge hasta la mitad por medio de un alambre en un recipiente que contiene alcohol ¿que volumen de alcohol desaloja?
La respuesta correcta es 180 centímetros cúbicos o 180 [tex]cm^{3}[/tex]
Explicación:
El primer paso para saber cuanto alcohol desaloja el prisma es calcular el volumen total del prisma. El volumen se puede encontrar usando la formula V (Volumen) = B (base) x h (altura). El proceso se muestra a continuación:
V = B x h
V = 36 [tex]cm^{2}[/tex] x 10 cm
V= 360 [tex]cm^{3}[/tex]
Finalmente, el volumen total del prisma debe dividirse en 2 considerando que solo la mitad del prisma fue sumergida y esta mitad equivale al volumen del alcohol desplazado.
360 [tex]cm^{3}[/tex] ÷ 2 = 180 [tex]cm^{3}[/tex]
El volumen de fluido desplazado es de 180 cm^3.
Sabemos que el objeto va a desplazar su propio volumen de fluido. Por lo tanto, necesitamos obtener el volumen del objeto a, este es el volumen del fluido que eventualmente será desplazado por el sólido.
El volumen del sólido es;
V = 36 cm^2 * 10 cm^2 = 360 cm^3
desde que se sumergió a la mitad, volumen de alcohol desplazado = 360 cm^3/2 = 180cm^3
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Which statement describes the interaction between the permanent magnets and the electromagnet in an electric motor? A. The current in the electromagnet is reversed by the permanent magnets B. The current in the permanent magnets is reversed by the electromagnet C. The poles of the permanent magnets are reversed by the electric field of the electromagnet. D. The metal loop in the electromagnet turns because of the magnetic field of the permanent magnets
Answer:D
Explanation:AP3X
The statement describes the interaction between the permanent magnets and the electromagnet in an electric motor is option D.
What is magnet?A substance which is negative charged at one end and positive charged at another end creating the magnetic field around it.
A bar is a magnet which can attract the particle which are charged. It has two poles North and South.
The permanent magnet create magnetic field very strong. The electromagnet is find in the electric motor. In the motor, loop made up of conductor is rotated by the effect of magnetic field of permanent magnet.
Thus, the correct option is D.
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Which describes an interaction within the musculoskeletal system?
Answer:
The musculoskeletal system involves the complex interactions of muscles, bones, and connective tissues.
When a muscle contracts, a bone will move. When a bone contracts, a muscle will move. When a ligament contracts, a tendon will move.
Answer:
A. when a muscle contracts , a bone will move
Explanation
thats the correct answer to this question on edg2021 :)
Alex wants to take a small road trip over the weekend, but
needs to be back before Monday. He travels 450 miles and
it takes him 9 hours. What unit of measurement should
Alex be measuring his speed with
Answer:
Miles is the distance unit. Hours is the time unit.
Explanation:
While the boys were playing baseball, one of the boys decides to kick his soccer ball high into the air. As the ball goes upward, which type of energy is increasing?
A.) Kinetic Energy
B.) Thermal Energy
C.) Potential Energy
D.) Mechanical Energy
A truck accelerates from 25 km/hr to 45 km/hr in 40 seconds. Calculate the average acceleration of the vehicle in m/s?.
Answer:
0.138889 m/s2
Explanation:
The average acceleration of the vehicle would be 0.139 meters/second².
What is acceleration?The rate of change of the velocity with respect to time is known as the acceleration of the object.
As given in the problem a truck accelerates from 25 kilometers/hour to 45 kilometers/hour in 40 seconds.
Let us first convert the velocities from kilometers/hour to meters/seconds
25 kilometers/hour ⇒ 25×1000/3600
= 6.94 meters/seconds
45 kilometers/seconds = 45×1000/3600
= 12.5 meters/seconds
acceleration = change in the velocity/time
=(12.5 -6.94)/40
=0.139 meters/second²
Thus, the acceleration of the truck would be 0.139 meters/second²
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Question 13 (1 point)
The genetic material of an offspring of sexually reproducing organisms is best described as-
a
Ob
identical to that of the other offspring
a copy of the genetic material of the father.
a copy of The genetic material of the mother
genes from both parents, in unique combinations
ос
Od
The genetic material of an offspring of sexually reproducing organisms is best described as genes from both parents in unique combinations.
SEXUAL REPRODUCTION:
Sexual reproduction is a type of reproduction that involves two organisms (a male and a female). The male organism produces a gamete called SPERM while the female organism produces a gamete called EGG. The gametes are produced via a process called MEIOSIS. Meiosis is a process of cell division whereby genetically different daughter cells are produced. The genetic variation is attributed to a process called crossing over, which is the exchange of genetic material between non-sister chromatids of homologous chromosomes. At the end of the fertilization process between male sperm and female egg, the genetic material of the offspring will contain genes from both parents in unique combinations.Learn more at: https://brainly.com/question/11622266?referrer=searchResults
state three ways of conserving energy
energy drinks
sitting
watching TV
Answer:
use natural lights
turn off electrical appliances..if not in use
check your wires every next Month
Definition of uniform speed
Answer:
Uniform Speed: A body is said to be moving with uniform speed, if it covers equal distances in equal intervals of time. Variable Speed: A body is said to be moving with variable speed if it covers unequal distances in equal intervals of time.
Explanation:
I got it from google
Answer:
Speed is a measure of how fast an object is moving at a given instant of time. It is a scalar quantity. Its unit is m/s. For a body covering equal distances in equal time intervals, the speed is called uniform speed.
Explanation:
What is the net force (including direction and magnitude) acting on the object on the above left?
Answer:
Explanation:
the net force on the right left is 25 N and is directed upward
the net force on the left one is zero because 200N force act upward and 200N force act downward so both cancel each other and net force is zero
i hope this will help you
The net force on the right left is 25 N and is directed upward.
The net force on the left one is zero because 200 N force act upward and 200 N force act downward so both cancel each other and net force is zero.
What is force?A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
By looking at both figure we get idea of net force after calculation,
The net force on the right left is 25 N and is directed upward.
The net force on the left one is zero because 200 N force act upward and 200 N force act downward so both cancel each other and net force is zero.
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Dorji weight 1500n.if the total surface area of soles of his feet is 0.5 m2 what is the pressure exerted by his body on the ground
Answer:
P = 3000 Pa
Explanation:
Weight of Dorji, W = F = mg = 1500 N
The total surface area of soles of his feet is 0.5 m²
We need to find the pressure exerted by his body on the ground. The pressure is equal to the force acting per unit area. So,
[tex]P=\dfrac{1500\ N}{0.5\ m^2}\\\\=3000\ Pa[/tex]
So, the pressure exerted by his body on the ground is 3000 Pa.
Please simplify and write the below paragraph.
The field lines due to a current in a
circular coil become straight and
perpendicular to the plane of the coil
at the centre. This is because at every
point of circular loop the concentric
circles representing the magnetic field
become larger and larger as we move
away from the wire.
Field lines become straight and perpendicular because every point of circular loop the concentric circles become larger and larger as we move away from the wire.
Which object has the most momentum?
A) a mass of 100, kg with a velocity of 2.0 m/sec
B) a mass of 100 kg with a velocity of 32.0 m/sec
C) a mass of 15 kg with a velocity of 200. m/ sec
Which of the following best describes the velocity of an object? *
8 points
A. 30 m/s
B. 30 m to the East
C. 30 m/s to the East
D. 30 m
A. 30 m/s . . . speed
B. 30 m to the East . . . displacement
C. 30 m/s to the East . . . velocity
D. 30 m . . . distance