Răspuns:
7: 4
Explicaţie:
Formula pentru calcularea cantității de căldură absorbită este exprimată ca;
Q = mc∆t
m este masa substanței
c este capacitatea termică specifică
∆t este schimbarea temperaturii
Conform legii calorimetriei, căldura pierdută de substanța rece = căldura câștigată de substanța fierbinte.
Folosind formula
(mc∆t) rece = (mc∆t) fierbinte
McCw∆tc = MhCw∆th
Deoarece au aceeași capacitate de căldură specifică, se vor anula. Ecuația devine;
Mc∆tc = Mh∆th ...... 1
Pentru apa rece;
∆tc = 45 ° C - 10 ° C
∆tc = 35 ° C
Pentru apa fierbinte:
∆th = 65 ° C - 45 ° C
∆th = 20 ° C
Înlocuiți în ecuația 1;
Mc (35) = Mh (20)
35Mc = 20Mh
Luând raportul dintre masa apei reci și cea fierbinte:
Mh / Mc = 35/20
Mh / Mc = 7/4
Prin urmare, lichidul trebuie amestecat împreună în raportul 7: 4
A projectile was fired from ground with 50 m/s initial velocity at 45 degree angle. How long will stay in the air? What is range? What is the maximum height the projectile?
Answer:
1. Time of flight = 7.22 s
2. Range = 255.10 m
3. Maximum height = 63.77 m
Explanation:
The following data were obtained from the question:
Initial velocity (u) = 50 m/s
Angle of projection (θ) = 45°
Time of flight (T) =?
Range (R) =?
Maximum height (H) =?
1. Determination of the time of flight
Initial velocity (u) = 50 m/s
Angle of projection (θ) = 45°
Acceleration due to gravity (g) = 9.8 m/s²
Time of flight (T) =?
T = 2uSine θ /g
T = 2 × 50 Sine 45 / 9.8
T = 100 × 0.7071 /9.8
T = 7.22 s
2. Determination of the range.
Initial velocity (u) = 50 m/s
Angle of projection (θ) = 45°
Acceleration due to gravity (g) = 9.8 m/s²
Range (R) =?
R = u²Sine 2θ /g
R = 50² × Sine (2×45) /9.8
R = 2500 × Sine 90 /9.8
R = 2500 × 1 / 9.8
R = 255.10 m
3. Determination of the maximum height.
Initial velocity (u) = 50 m/s
Angle of projection (θ) = 45°
Acceleration due to gravity (g) = 9.8 m/s²
Maximum height (H) =
H = u²Sine²θ /2g
H = 50² × (Sine 45)² / 2 × 9.8
H = 2500 × (0.7071)² / 19.6
H = 63.77 m
Answer:
Time spent in the air is 7.22 sThe range of the projectile is 255.1 mThe maximum height of the projectile is 63.77 mExplanation:
Given;
initial velocity of projection, u = 50 m/s
angle of projection, θ = 45°
Time spent in the air is the time of flight, given as;
[tex]T = \frac{2usin \theta}{g}\\\\T = \frac{2(50)sin (45)}{9.8}\\\\T = 7.22 \ s[/tex]
The range of the projectile is given by;
[tex]R = \frac{u^2sin(2\theta)}{g}\\\\R = \frac{u^2sin(2*45)}{g}\\\\ R = \frac{u^2sin(90)}{g}\\\\ R = \frac{u^2(1)}{g}\\\\R=R_{max} = \frac{u^2}{g} =\frac{50^2}{9.8} = 255.1 \ m[/tex]
The maximum height of the projectile is given by;
[tex]H = \frac{u^2sin^2\theta}{2g}\\\\H = \frac{(50)^2sin^2(45)}{2*9.8}\\\\H = 63.77 \ m[/tex]
Device A has a current of 0.4 A and a resistance of 3 Ω. Device B has a current of 0.6 A and a resistance of 3Ω. Which device would be more energy efficient?
Your answer would be Device A.
Answer:
Device A because it would use more voltage :D
Explanation:
Find the range of a projectile launched at an angle of 30⁰with an initial velocity of 20m/s
Initial velocity of projection (u) = 20 m/s
Angle of projection (θ) = 30°
Formula of Horizontal Range of Projectile:
[tex] \boxed{ \bf{R = \dfrac{2u^2 sin\theta .cos \theta}{g}}}[/tex]
By substituting values in the formula, we get:
[tex] \rm \longrightarrow R = \dfrac{2 \times 20^2 \times sin30 \degree \times cos 30 \degree}{10} \\ \\ \rm \longrightarrow R = \dfrac{ \cancel{2} \times 40 \cancel{0} \times \dfrac{ \sqrt{3} }{ 2} \times \dfrac{1}{\cancel{2}} }{ \cancel{10}} \\ \\ \rm \longrightarrow R =40 \times \dfrac{ \sqrt{3} }{ 2} \\ \\ \rm \longrightarrow R =20 \sqrt{3} \: m \\ \\ \rm \longrightarrow R =34.641 \: m[/tex]
[tex] \therefore [/tex] Horizontal Range of Projectile (R) = 34.641 m
a ball accelerate downward at 9.8 m/s2 with 1.7 of force. What is the mass of the ball?
Answer:
0.14 kg
Explanation:
m=F/a = (1.4N/9.8 m/s/s) =0.14 kg
If you are in a car at a stop sign and then the driver
presses on the gas pedal really hard, which way is the car
accelerating?
Answer:
it wont be because the hand brake would be on
This man proposed that all matter was composed of atoms
Answer:
John Dalton
Explanation:
how is force spread over long and short durations of time?
I think you're having trouble with it only because of how you're trying to look at it.
Don't try to imagine "spreading force" over time. Just think about how long the force lasts !
Like . . .
If you push your doll stroller for 5 seconds, you'll get it up to a certain speed.
Next time, if you push it again with the same force, but you keep pushing for TEN seconds, you'll get it up to a faster speed.
Technically:
(force • time) = impulse.
You gave it more impulse the second time, so it got more momentum from you.
if a truck hits a bug, they exert the exact same force on each other. That force is strong enough to squish the bug, but not strong enough to damage the truck. The force makes the bug accelerate very rapidly, but the truck keeps moving at a constant velocity. Do you agree? Why or why not? HELP XD
Which situation has the most potential energy
А.
a 100 kg student diving from 2 meters off the water
OOO
B.
a 100 kg student diving from 3 meters off the water
C
a 200 kg student diving from 2 meters off the water
D.
a 200 kg student diving from 3 meters off the water
Answer:
B
Explanation: you are staying longr to jump 3 meters than one meter
please help
a puck moves 2.35 m/s in a -22 degree direction a hockey stick pushes it for .215 s changing its velocity to 6.42 m/s in a 50 degree direction. What is delta x?
Answer:
0.678m
Explanation:
Find: Δx
Δx = ½ (v + v₀) t
Δx = ½ (4.127 m/s + 2.179 m/s) (0.215 s)
Δx = 0.678 m
What two things must you know to describe the motion of an object? __________________________________________________________________________
Distance is _________________________________________________________________
What is the displacement of a cyclist, who travels 1 mile north, then 1 mile east, and finally 1 mile south? ___________________________
Define speed ________________________________________________________________
How do speed and velocity differ? ______________________________________________
__________________________________________________________________________
How do velocities combine? In opposite directions? ________________________________ In the same direction? ________________________________________________________
A river flows at a velocity of 3 km/h relative to the riverbank. A boat moves upstream at a velocity of 15 km/h relative to the river. What is the velocity of the boat relative to the riverbank? ___________________________________
The rate at which velocity changes is called ________________________
True or false? Acceleration is the result of increases or decreases in speed.
A horse on a carousel that is moving at a constant speed is accelerating because _________________________________________________________________________
True or false? When the final velocity is less than the initial velocity of an object, the acceleration is negative.
The total distance traveled divided by the total time is _______________________
What are some common units for speed (give at least two) _____________ ___________
Define velocity ____________________________________________________________
Define acceleration _________________________________________________________
A quantity that has both magnitude and direction is called a _________________.
WILL MARK BRAINLIEST PLEASE HELP DUE IN 2 MINS
On a distance-time graph speed is a ____________ line and thus a ____________ graph.
On a distance-time graph acceleration is a ___________ line and thus a _______________ graph.
Answer:
velocity is vector Quantity
Which Box in the diagram above, should this picture go into?
Box A
ООО
O Box B
O Box C
Plzz answerr idk
b) If the voltage of the fuel cell used in a circuit is 9.0 V and the resistance of the wire used in the circuit is 560 22,
what is the current running through the circuit? Use correct units at all times!
Formula:
Calculation:
Answer:
I
Answer:
current (I)=V/R
current (I)=9.0/56022
so I=1.607×10 in the power of negative four Amperes (A)
Amanda studies a waveform. She labels parts of the waveform using variables (P,Q,R, and S), as shown in the image.
Which label part represents the wavelength
Answer:
Q
Explanation:
To know which symbol defines the wavelength, we must know the definition of wavelength.
Wavelength can be defined as the distance between two successive crests (i.e the highest part) or troughs (the lowest part) of a wave.
Considering the diagram given above, Q shows the distance between two successive crests (i.e the highest part) of the wave. Therefore, Q is the wavelength of the wave given in the diagram above.
Sharon pours salt into a glass of water. The salt dissolves. The substance in the glass is a_________
study island
Answer:
Issa Mixture.
A salt is a compound. ... Na exists in sodium compounds and Cl as Cl2 or chlorinated compounds. A common example would be table salt where both exist( Sodium Chloride). Sodium Chloride solution consisting of NaCl and water is a mixture. An example would be sea water which consists of several salts. Ur welcome.
Explanation: and
The salt is the solute; water is the solvent. Mixed together they become a solution.
what force is the total force felt by an object?
Answer:
net force
Explanation:
Net force felt by an object.
Which TWO statements about the substances in the experiment are true?
A. Quartz is harder than chalk.
B. Water has a higher surface tension than salty water.
C. Soapy water has a higher surface tension than plain water.
D. Graphite is harder than quartz.
Answer:
answer A and B
A. Quartz is harder than chalk.
B. Water has a higher surface tension than salty water.
Explanation:
did the test !
The two statements about the substances in the experiment are true are
Quartz is harder than chalk and the Water has a higher surface tension than salty water. Therefore the correct options are option A and option B.
What is the matter?Anything which has mass and occupies spaces is known as matter, mainly there are four states of matter solid liquid gases, and plasma.
These different states of matter have different characteristics according to which they vary their volume and shape.
The hardness of quartz is more than that of chalk.
The surface tension is because of the cohesive force of the molecules among them, surface tension can be defined as force per unit length and represented in the unit N/s.
The cohesive force of attraction is more in water as compared to that of salty water therefore the surface tension of the water is more than that of salty water.
The two statements about the substances in the experiment are true are
Quartz is harder than chalk and the Water has a higher surface tension than salty water. Therefore the correct options are option A and option B.
learn more about the matter here
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A student, who weighs 720N, is standing on a bathroom scale and riding an elevator that is moving downwards with a speed that is decreasing at a rate of 3.1m/s2.
What is the student's mass?
What is the net force on the student?
What value does the scale read?
Answer:
1) The mass of the student is approximately 73.39 kg
2) The net force on the student is approximately 947.523 N
3) The value the scale will read is approximately 96.59 kg
Explanation:
The given parameters are;
The weight of the student = 720 N
The speed at which the elevator is decreasing = 3.1 m/s²
1) The weight of the student = The mass of the student × The acceleration due to gravity
The acceleration due to gravity is a constant = 9.81 m/s²
Substituting the known values gives;
720 N = The mass of the student × 9.81 m/s²
∴ The mass of the student = 720 N/(9.81 m/s²) ≈ 73.39 kg
2) The forces acting on the student are;
i) The force of gravity which is the weight of the student acting downwards
ii) The inertia force of the slowing elevator acting downwards in the same direction as the weight of the student
The net force, [tex]F_{net}[/tex] = The weight of the student + The inertia force of the slowing elevator
∴ The net force, [tex]F_{net}[/tex] = 720 N + 73.39 kg × 3.1 m/s² ≈ 947.523 N
3) The scale will read the mass of the student as follows;
Mass reading of student on the scale = Force on scale/9.81
∴ Mass reading of student on the scale = 947.523/9.81 ≈ 96.59 kg
The value the scale will read = 96.59 kg.
The mass of student is, 73.46 kg.
The net force acting on the student is 942.72 N.
The reading of the scale is 96.70 kg
Given data:
The weight of student is, W = 720 N.
The magnitude of acceleration is, [tex]a = 3.1 \;\rm m/s^{2}[/tex].
The standard expression for the weight is,
[tex]W =mg[/tex]
Here, g is the gravitational acceleration. And m is the mass of student.
Solving as,
[tex]W =mg\\\\720 = m \times 9.8\\\\m = 73.46 \;\rm kg[/tex]
Thus, the mass of student is, 73.46 kg.
Since, the force of gravity which is the weight of the student acting downwards . The inertia force of the slowing elevator acting downwards in the same direction as the weight of the student. Then the net force is,
[tex]F_{net} = W+(ma)[/tex]
Solving as,
[tex]F_{net} = 720+(73.46 \times 3.1)\\\\F_{net}=947.72 \;\rm N[/tex]
Thus, we can conclude that the net force acting on the student is 942.72 N.
The reading of the scale is given as,
[tex]reading=\dfrac{F_{net}}{g}[/tex]
Solving as,
[tex]reading = \dfrac{947.72}{9.8}\\\\reading=96.70 \;\rm kg[/tex]
Thus, we can conclude the reading of the scale is 96.70 kg.
Learn more about the concept of gravitational acceleration here:
https://brainly.com/question/25316208
A man has a mass of 66 kg on Earth. What is his weight in Newtons?
Answer:
answer is 66 kilograms-force = 647.2389 newtons
Explanation:
Answer:
[tex]\boxed {\boxed {\sf 646.8 \ Newtons }}[/tex]
Explanation:
Weight in Newtons can be found by multiplying the mass times the acceleration of gravity.
[tex]W=m*g[/tex]
The mass of the man is 66 kilograms on Earth.
Earth has an acceleration of gravity that is 9.8 meters per square second.
[tex]m= 66 \ kg \\g=9.8 \ m/s^2[/tex]
Substitute the values into the formula.
[tex]W=66 \ kg *9.8 \ m/s^2[/tex]
Multiply.
[tex]W=646.8 \ kg*m/s^2[/tex]
1 kg * m/s² is equal to 1 Newton, therefore our answer of 646.8 kg *m/s² is also equal to 646.8 Newtons, or N.
[tex]W=646.8 \ N[/tex]
The man's weight in Newtons in 646.8 Newtons.
A rocket, initially at rest on the ground, accelerates straight upward from rest with constant (net) acceleration 53.9 m/s2 . The acceleration period lasts for time 6.00 s until the fuel is exhausted. After that, the rocket is in free fall.
Find the maximum height ymax reached by the rocket. Ignore air resistance and assume a constant free-fall acceleration equal to 9.80 m/s2 .
Answer:
maximum height reach by rockect =970.2metre
Explanation:
which theory is a famous for quantum physics
Which statements correctly describe the properties of air? Select three options. Air has mass but no weight. Air pressure is created by the weight of the atmosphere pushing on Earth’s surface. Pressure is a measure of how tightly molecules are packed. Denser air is heavier than less dense air. Air is less dense at higher altitudes.
Answer:
Air pressure is created by the weight of the atmosphere pushing on Earth’s surface.
Denser air is heavier than less dense air.
Air is less dense at higher altitudes.
Explanation:
Based on the properties of air, the correct options from the given statements are:
Denser air is heavier than less dense airAir is less dense at higher altitudes.Air pressure is created by the weight of the atmosphere pushing on Earth’s surfaceWhat is air?Air is a mixture of gases in the atmosphere which consists of nitrigen, oxygen, carbon dioxide and noble gas as well as other trace partickes like water vapor.
Some properties of air include:
air is a mixture of gases Air has mass and weight.Air pressure is created by the weight of the atmosphere pushing on Earth’s surfaceDenser air is heavier than less dense airAir is less dense at higher altitudes.Therefore, the correct options from the given statements are:
Denser air is heavier than less dense airAir is less dense at higher altitudes.Air pressure is created by the weight of the atmosphere pushing on Earth’s surfaceLearn more about air at: https://brainly.com/question/441281
HELP ME PLEASE
I don’t know what the answer is.
Answer:
Hey buddy, here is your answer. Hope it helps you.
Explanation:
Solids.Sound travels fastest through solids. This is because molecules in a solid are packed against each other. When a vibration begins, the molecules of a solid immediately collide and the compression wave travels rapidly.Sound moves slowest through a gas. That’s because the molecules in a gas are spaced very far apart. In order for sound to travel through air, the floating molecules of matter must vibrate and collide to form compression waves. Because the molecules of matter in a gas are spaced far apart, sound moves slowest through a gas.
Sound travels faster in liquids than in gases because molecules are packed more closely together. This means that when the water molecules begin to vibrate, they quickly begin to collide with each other forming a rapidly moving compression wave.
hey guys, l need some help! what is the weight of potatoes of mass 75 kg on the surface of the earth? (g=9.8m/s square) ans=735N l need process
Answer:
735N
Explanation:
Weight is a measurement of force.
F = Force
m = mass
a = acceleration
F = m*a
F = 75kg*9.8m/s²
F = 735N
Tyler drives 50km north. Tyler then drives back 30km south. What distance did he cover? What was his displacement?
Answer:
80 km is distance and 30km north is displacement
Explanation:
distance= 50+30=80km
displacement= 50-20=30
his displacement is 30km north
When Tyler drives 50 km north and then drives back 30 km south, we have:
1. The distance that he covers is 80 km.
2. Tylor's displacement is 20 km.
1. The distance is a scalar that is given by the sum of the kilometers traveled by Tyler as follows:
[tex] d = d_{1} + d_{2} = 50 km + 30 km = 80 km [/tex]
Hence, the distance traveled by Tyler was 80 km.
2. The displacement is a vector that depends on the direction of travel. Takin the north direction as positive we have:
[tex] x = x_{1} + x_{2} = 50 km + (-30 km) = 20 km [/tex]
Therefore, Tyler's displacement is 20 km.
You can find more about displacement and distance here: https://brainly.com/question/4307551?referrer=searchResults
I hope it helps you!
how do the early efforts of women during the suffrage movement compare to the later years
The idea that women's liberation is also men's liberation arouses the awakening of feminism. In 1966 Frieden and other feminists founded the National Organization for Women. Then other women's organizations for equal rights were formed in the United States and Western Europe. These organizations sought to overturn discriminatory laws and practices that forced women to hold down their status, such as discrimination in matters of contract and property ownership, employment and wages, the treatment of wage income, and issues relating to sex and child-bearing. The growing feminist movement more broadly seeks to change social stereotypes that women are more vulnerable, passive and dependent, less rational and emotionally reactive than men. Feminism strives for greater freedom for women in the workplace and makes them financially and psychologically independent of men, if they wish. Feminists criticized society's general emphasis on women as objects of sexual desire and sought to raise women's awareness and expand their opportunities in order to achieve equality with men. Another objective of feminism is to promote women's participation in all areas of political decision-making and social life.
Which of the following statements is true?
If a hypothesis is proven false, a mistake has been made in the experiment.
The independent variable is what changes as a result of the dependent variable.
Changes in the independent variable cause changes in the dependent variable.
Once a hypothesis is proven true, it becomes a theory and cannot be disproved.
Answer:
[tex]Changes \: in \: the \: independent \: variable \: cause \\ changes \: in \: the \: dependent \: variable.[/tex]
What is the mass of a man who accelerates 4 m/s2 under the action of a 300 N net force?
Answer:
F = m*a
therefore m = F / a
m = 100 / 5 = 20 kg?
hope this helped you
Explanation:
The required mass of man, undergoing the acceleration is of 75 kg.
Given data:
The magnitude of acceleration of man is, a = 4 m/s².
The magnitude of action force on the man is, F = 300 N.
Here we can apply the Newton's second law of motion, which says that the applied force causes the acceleration of any object. Where the applied force is equal to the mass of object and the magnitude of acceleration of object.
Therefore,
F = ma
Solving as,
300 = m × 4
m = 300/4
m = 75 kg
Thus, we can conclude that the mass of man, undergoing the acceleration is of 75 kg.
Learn more about the Newton's second law here:
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Which describes the role of oxygen in photosynthesis? *
It is a reactant, so it is released by the plant.
It is a product, so it is released by the plant.
It is a reactant, so it enters the plant.
It is a product, so it enters the plant.
Answer:
It is a product, so it is released by the plant.
Explanation:
[tex]6CO2 + 6H2O[/tex] → [tex]C6H12O6 + 6O2[/tex]
The plant uses water and carbon dioxide to create glucose and oxygen. Glucose is plant food, and Oxygen is given off as a byproduct.
Answer:
It is a product, so it is released by the plant.
Explanation:
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