Trafegando por uma avenida com velocidade constante de 54km/h, num dado instante, o motorista percebe o sinal vermelho à sua frente e pisa no freio até que, depois de 5 s, o automóvel para. Determine a aceleração escalar média do carro nesse intervalo de tempo em Km/h dividido por s e em m/s²
Answer:
The acceleration is - 3 m/s2.
Explanation:
initial speed, u = 54 km/h = 15 m/s
final speed, v = 0
time, t = 5 s
Let the acceleration is a.
use first equation of motion
v = u + at
0 = 15 + a x 5
a = - 3 m/s2
Tom is throwing an baseball at an aluminum can,
present an argument about the likely kinetic energy of the ball before and after.
describe the evidence that would support the argument.
present an argument about the likely kinetic energy of the can before and after.
describe the evidence that would support the argument.
Answer:
The question relates to the conservation of energy principle, the conservation of the linear momentum, and Newton's Laws of motion
Part A
1) Tom throwing a baseball at a can
The initial velocity of the baseball = v₂
The initial kinetic energy of the baseball, K.E.₂ = (1/2)·m₂·v₂²
∴ The final kinetic energy of the baseball, K.E.₂' = (1/2)·m₂·v₂'² < (1/2)·m₂·v₂²
Therefore, the energy of the ball before the collision is lesser than the energy of the ball after the collision
2) The evidence that would likely support the claim is that the baseball's height above the ground reduces rapidly immediately after the collision which is due to the reduced velocity, and therefore, the reduced (kinetic) energy
The final velocity of the baseball v₂' < v₂
Part B
1) The argument
The initial velocity of the can = v₁ = 0 (The can is initially at rest)
The initial kinetic energy of the can, K.E.₁ = (1/2)·m₁·v₁² = 0
The final velocity of the can v₁' > v₁ = 0
∴ The final kinetic energy of the can, K.E.₁ = (1/2)·m₁·v₁² > 0
Given that the velocity of the can increases from zero to a positive value after collision with the baseball, the kinetic energy of the can is increased from zero before the collision to a positive value after the collision
2) An evidence in support of the argument is the motion of the can which was initially at rest which is an indication of increase in energy podded by the can
Explanation:
A certain AM radio wave has a frequency of 24Hz. Given that radio waves travel at 3 m/s, what is the wavelength of this radio wave?
Answer:
Wavelength of AM radio wave = 0.125 meter
Explanation:
Given:
Frequency of AM radio wave = 24 Hz
Velocity of AM radio wave = 3 m/s
Find:
Wavelength of AM radio wave
Computation:
Wavelength = Velocity / Frequency
Wavelength of AM radio wave = Velocity of AM radio wave / Frequency of AM radio wave
Wavelength of AM radio wave = 3 / 24
Wavelength of AM radio wave = 0.125 meter
What quantities are needed to calculate angular momentum? There is more than one answer.
A.
Radius
B.
Acceleration
C.
Mass
D.
Velocity
Answer
Velocity, Mass, and Radius
Explanation:
radius is what the size of the thing moving and the mass and velocity is both part of momentum because of speed and direction, BUT acceleration is both the change in speed and direction, not speed for direction themselves, so it is Velocity, Mass, and Radius
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An object is fired from the ground at 100. m/s at an angle of 30° with the horizontal.
a) Calculate the horizontal and vertical components of the initial velocity
b) After 2.0 seconds, how far has the object traveled in the horizontal direction?
c) How high is the object at this point
Answer:
a. V_y = 50m/s and V_x = 86.6m/s
b. d_x = 173.2m
c. d_y = 80.38m
Explanation:
V_x = 100m/s*cos(30°)
V_x = 86.6m/s
V_y = 100m/s*sin(30°)
V_y = 50m/s
D_x = v_x*t
d_x = 86.6m/s*2s
d_x = 173.2m
v_f = 50m/s+(-9.81m/s²)*2s
v_f = 30.38m/s
d_y = .5*(30.38m/s+50m/s)*2s
d_y = 80.38m
a man runs 1200m on a straight line in 4 min . find his velocity.
Answer:
5m/sec^2
Explanation:
Distance=1200m
Time=4 min
1=60sec
4=4 x 60
=240sec
Velocity=Distance/Time
Velocity=1200/240
Velocity=5m/sec^2
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A first aid provider is trained to do the following except:
A) diagnose the victims condition
B) recognize, asses and prioritize the need for first aid
C) seek professional medical assistance when necessary
D) provide appropriate first aid care
what is substances ?????
Substance:-
A substance is matter which has a specific composition and specific properties.
Molten iron has a density of 7.0 g/cm. In its solid state, iron has a density of
8.0 g/cm?
Calculate the volume of 10 kg of molten iron.
Volume =
Dierks is a scientist who is currently focusing on developing a ceramic that holds heat well. He is trying to develop the ceramic to make a higher-temperature curling iron. The application of solid-state physics Dierks is most likely involved in is (BLANK).
Answer:
i need this 2
Explanation:
Answer:
Materials Science
Explanation:
Materials Science: "The study of the characteristics of materials such as glass, plastics, and metals."
Ceramics is a glass so they are studying materials science.
Hope this helped ! :)
The distance between an object and a reference point is the object's what?
Answer:
Displacement
Explanation:
The distance between an object and a certain reference point is called displacement. This is not to be confused with distance, which represents the total distance the object has travelled to get a certain point, regardless of how long it is. Displacement always represents the shortest distance (a straight line) between the initial and final points.
Answer:
Displacement is the distance and direction of an object's change in position from a reference point. Suppose a runner jogs to the 50-m mark and then turns around and runs back to the 20-m mark.
define pressure snd state its SI units to
Pressure is defined as the perpendicular force acting per unit area.
Its SI unit is pascal.
Explanation:
Formula to calculate pressure is,
P=F/A
Where as,
P = Pressure
F = Force
A = Area
Its SI unit is pascal(pa).
A piece of glass has mass of 1 kg and a density of 800 kgm-³ negative cubed calculate its volume
Explanation:
we know that
v = m/d
or; v=1kg/800kgm^3
or; v=0. 00125m
A motor has an internal resistance of 12.1 Ω. The motor is in a circuit with a current of
4.0 Amps
What is the voltage?
Answer:
Explanation:
V = I * R
V = 4 * 12.1 = 48.4 v
Can someone help me :)
Answer:
undergone a chemical change
Explanation:
Answer:
undergone a chemical change
In an electrical circuit 200mC of charge flows through a 50kohm resistor in 90 seconds. What is the power
Answer: [tex]0.2464\ W[/tex]
Explanation:
Given
Charge [tex]Q=200\ mC[/tex]
Resistance [tex]R=50\ k\Omega[/tex]
Time [tex]t=90\ s[/tex]
Charge is the amount of current flown in a particular time
[tex]Q=It\\\Rightarrow 200\times 10^{-3}=I\times 90\\\\\Rightarrow I=\dfrac{200\times 10^{-3}}{90}\\\\\Rightarrow I=2.22\times 10^{-3}\ A[/tex]
Power is the given by [tex]P=I^2R[/tex]
Insert values
[tex]\Rightarrow P=\left(2.22\times 10^{-3}\right)^2\times 50\times 10^3\\\\\Rightarrow P=246.42\times 10^{-3}\ W\\\\\Rightarrow P=0.2464\ W[/tex]
The power is in the circuit is [tex]0.2464\ W[/tex].
A rope horizontally pulls a massive object lying on a surface with friction with a constant
velocity. What describes the force on the rope?
Answer:
Equal to the frictional force
Explanation:
Question; The options given with regards to a similar question posted online are;
A. Equal (equivalent) to the frictional force
B. Larger than the frictional force
C. Equal to the object's weight
D. More than the object's weight
Explanation
According to Newton's first law of motion, every object shall remain at rest or continue moving with uniform (constant speed) motion unless there is a net force acting on the object
Given that the velocity of the massive block, lying on the surface that has friction, being pulled by the rope = Constant
Therefore;
The net force acting on the moving block while being pulled by the rope = 0
From which we have;
The pulling force = The resistive force
Where;
The pulling force = The (pulling) force (applied) on the rope
The resistive force = The frictional force of the surface which tends to prevent the motion of the block
Therefore, given that the net force acting on the block = 0
The force on the rope = The frictional force (of the surface)
The correct option is option A. Equal to the frictional force.
You might have noticed that a feather falls slowly toward the ground, while a ball falls rapidly. Which statement correctly explains the motion of these objects?
1. The ball does not experience fluid friction as it falls.
2. Gravity is the only force acting on the feather and the ball.
3.The acceleration of the ball and feather are the same.
4. The feather experiences more fluid friction than the ball.
Answer:
4. the feather experiences more fluid friction than the ball
A crate of mass 2 kg is being pulled to the right across a rough horizontal surface by constant force F. The force F is applied at an angle of 20° to the horizontal, as shown in the diagram. how can l draw a labelled free body showing all force
Explanation:
Finding the (maximum) respective prime powers would yield the answer. Also we need not ... Is perfectly divisible by 720^n? ... So we can say that for any positive value of n it not
divisible.
For the normal force in the drawing to have the same magnitude at all points on the vertical track, the stunt driver must adjust the speed to be different at different points. Suppose, for example, that the track has a radius of 3.25 m and that the driver goes past point 1 at the bottom with a speed of 20.2 m/s. What speed must she have at point 3, so that the normal force at the top has the same magnitude as it did at the bottom
Answer:
The speed she must have at point 3 is approximately 21.72 m/s
Explanation:
The given parameters are;
The radius of the track, r = 3.25 m
The speed with which the driver goes past point 1, v₁ = 20.2 m/s
Let, 'm', represent the mass of the driver and the car, and let v₃ represent the velocity at point 3, based on the diagram and solution method from a similar question online, we have;
At point 1, The net force, [tex]F_{NET} = F_N - F_g[/tex]
The net force, [tex]F_{NET}[/tex], is the centrifugal force, therefore;
[tex]F_{NET} = \dfrac{m \cdot v_1^2}{r}[/tex]
[tex]F_g[/tex] = The force of gravity on the car (the weight of the car) = m·g
[tex]F_N_1[/tex] = The normal reaction at point 1
Therefore, we have;
[tex]F_{NET} = \dfrac{m \cdot v_1^2}{r} = F_N_1 - F_g = F_N_1 - m \cdot g[/tex]
[tex]F_N_1= \dfrac{m \cdot v_1^2}{r} + m \cdot g = m\cdot \left(\dfrac{ v_1^2}{r} + g \right)[/tex]
[tex]F_N_1 = m\cdot \left(\dfrac{ v_1^2}{r} + g \right)[/tex]
At point 3, The net force, [tex]F_{NET} = F_N_3 + F_g[/tex]
Where;
[tex]F_{N3}[/tex] = The normal reaction at point 3
Therefore;
[tex]F_N_3= F_{NET} - F_g = \dfrac{m \cdot v_3^2}{r} - m \cdot g = m\cdot \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
For the normal force to be the same, we get;
[tex]F_{N1} = F_{N3}[/tex]
Therefore;
[tex]m\cdot \left(\dfrac{ v_1^2}{r} + g \right) = m\cdot \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
[tex]\left(\dfrac{ v_1^2}{r} + g \right) = \left(\dfrac{ v_3^2}{r} - g \right)[/tex]
[tex]v_3^2 = r \times \left(\dfrac{ v_1^2}{r} + g + g \right) = v_1^2 + 2\cdot g \cdot r[/tex]
[tex]v_3 = \sqrt{v_1^2 + 2\cdot g \cdot r}[/tex]
Where;
g = The acceleration due to gravity ≈ 9.81 m/s²
Therefore;
v₃ = √(20.2² + 2 × 9.81 × 3.25) ≈ 21.72 m/s
The speed she must have at point 3, so that the normal force at the top has the same magnitude as it did at the bottom, v₃ ≈ 21.72 m/s
The velocity of sound in a medium increases with increasing
a. distance
b. amplitude
c. temperature
d. time
c- temperature
The speed of sound increases with increasing temperature .
what current flows between a voltage of 120v across a resistance of 30Ω?
Answer:
4 amp
Explanation:
From ohm's law,
V=IR
so,
I=V/R
I=120/30
I=4amp ans..
Cuatro contenedores idénticos tienen la misma cantidad de gas helio a la misma temperatura inicial. Los recipientes también cuentan con un émbolo móvil que no permite que el helio escape. Cada muestra de gas sigue un proceso distinto como se describe a continuación: Muestra 1: 500 J de calor salen del gas y este realiza 300 J de trabajo. Muestra 2: 500 J de calor entran al gas y este realiza 300 J de trabajo. Muestra 3: 500 J de calor salen del gas y se hace un trabajo de 300 J sobre él. Muestra 4: 500 J de calor entran al gas y se hace un trabajo de 300 J sobre él.
Answer:
1) ΔE = -800 J, 2) ΔE = 200 J, 3) ΔE = -200 J, 4) ΔE = 800 J
Explanation:
For this exercise let's use the first law of thermodynamics
ΔE = Q + W
Where we will apply this expression to several cases
1) output Q = 500 J and does work of W = 300 J.
The two processes involve an energy output
ΔE = - 500 - 300
ΔE = -800 J
Therefore, the internal energy of the gas decreases by this amount,
2) enter Q = 500J and do work of W = 300 J
Positive heat is added and does negative work
ΔE = 500 - 300
ΔE = 200 J
3) they leave Q = 500 J and do (work on the gas) W = 300J
negative heat and positive work come out
ΔE = -500 + 300
ΔE = -200 J
4) heat enters Q = 500 J, work on gas W = 300 J
both positive
ΔE = 500 + 300
ΔE = 800 J
Determine the value of F
l will give BRAINLIEST.....
Answer:
10 N
Explanation:
From the diagram,
Applying the principle of moment,
Sum of clockwise moment = sum of anti clockwise moment.
Assuming: the 10 N is placed on the 5 cm mark, F is placed on the 40 cm mark, The 25 N is placed on the 10 cm mark, the 30 N is placed on the 75 cm mark, and the 40 N is placed on the 80 cm mark.
Therefore,
10(50-5)+F(50-40)+40(80-50) = 30(75-50)+25(50-10)
450+10F+1200 = 750+1000
10F+1650 = 1750
10F = 1750-1650
10F = 100
F = 100/10
F = 10 N
Which statement describes the possible interaction(s) between two objects
caused by the electric, magnetic, or gravitational force between them?
O A. Electric and gravitational forces only cause objects to repel each
other, and magnetic forces only cause objects to be attracted to
each other.
O B. All three types of forces only cause the objects to repel each other.
O C. Gravitational forces only cause objects to be attracted to each
other, and magnetic and electric forces can cause objects to
attract or repel each other.
O D. All three types of forces only cause the objects to be attrachyd to
each other.
The statement which describes the possible interaction(s) between two objects caused by the electric, magnetic, or gravitational force between them is:
Gravitational forces only cause objects to be attracted to each other, and magnetic and electric forces can cause objects to
What is force?Force can be defined as the push or pull on an object with mass that causes it to change its velocity
So therefore, the statement which describes the possible interaction(s) between two objects caused by the electric, magnetic, or gravitational force between them is:
Gravitational forces only cause objects to be attracted to each
other, and magnetic and electric forces can cause objects to
Learn more force:
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what is accerlation due to gravity??
Answer:
When an object falls, gravity pulls the object towards the ground and causes the object to accelerate by 9.8m/s each second. Regardless of mass, every object accelerates at the same rate (9.8m/s) when dropped unless there´s air resistance.
¿Cuál es la presión que soporta un buzo sumergido a 10 metros de profundidad en el mar? Datos: Densidad del agua de mar = 1025 kg/m^3 Presión atmosférica 101325 Pa Y por que
Answer:
The pressure at the depth is 201775 Pa.
Explanation:
Depth, h = 10 m
density, d = 1025 kg/m3
atmospheric pressure, Po = 101325 Pa
The total pressure at the depth is
P = Po + h d g
P = 101325 + 10 x 1025 x 9.8
P = 101325 + 100450
P = 201775 Pa
I pull a wagon with a 30 kg child in it with a FORCE of 2000 N. The handle makes a 60 degree angle with the horizon. If I pull the child for a distance of 0.75 miles (1 mile = 1600 m), how much work did I do?
Answer:
1200000 J
Explanation:
Applying,
W = Fdcos∅....................... Equation 1
Where W = Workdone, F = Force applied to pull the wagon, d = distance, ∅ = angle with the horizontal.
From the question,
Given: F = 2000 N, d = 0.75 miles = (0.75×1600) = 1200 m, ∅ = 60°
Substitute these values into equation 1
W = 2000×1200×cos60°
W = 2000×1200×0.5
W = 1200000 J
Hence the work done in pulling the wagon is 1200000 J
Which of earths spheres are involved in the water cycle
Answer:
All of the major spheres of the Earth are involved in the water cycle. The four spheres are the atmosphere, hydrosphere, lithosphere, and biosphere....
Explanation:
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Which of earths spheres are involved in the water cycle ?
Hydrosphere, atmosphere, lithosphere, and biosphere are all sphere involved in the water cycle.What is Hydrosphere ?
Hydrosphere is a discontinuous layer of water at or near Earth’s surface. It includes all liquid and frozen surface waters, groundwater held in soil and rock, and atmospheric water vapour.What is atmosphere?
Atmosphere refers to the gases surrounding a star or planetary body held in place by gravity. ... The composition of the Earth's atmosphere is about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, with water vapor, carbon dioxide, and other gases.What is lithosphere?
A lithosphere is the rigid, outermost shell of a terrestrial-type planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of thousands of years or greater.What is Biosphere?
The biosphere, also known as the ecosphere, is the worldwide sum of all ecosystems. It can also be termed the zone of life on Earth. The biosphere is virtually a closed system with regards to matter, with minimal inputs and outputs.#CarryOnLearning
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What is work and give an example? (science newton's law)
Answer:
Work is ability if application of energy.
Such as pushing a wheel barrow through a distance ( Newton's third law )
Work is the ability to do something.