Answer:
The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.
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A 20-N force acts on a 5-kg object at rest. How fast will
the object accelerate on a frictionless surface?
A. 15 m/s^2
B. 25 m/s^2
C. 4 m/s^2
D. 100 m/s^2
Answer:
C.
Explanation:
Force = Mass * Acceleration
So 20 = 5* Acceleration
4 = Acceleration
The acceleration of the object is 4 m/s².
To find the acceleration, the given values are:
Force = 20 N
Mass = 5 kg
Define acceleration.Definition:
As it was given as the values of Force and mass, here acceleration definition depends on the Newton's second law of motion.
Using the second law of motion, the force will be equal to the product of the mass and the acceleration.
As formula,
F = ma Newton
Here, to find acceleration,
a =f/ m
Substituting the values,
= 20 / 5
a = 4m/s².
So, the acceleration was 4 m/s². The Option C is the correct answer.
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In which phase(s) of matter are the atoms closely packed but still able to slide past each other? O gas O liquid O solid and gas O liquid and solid Save and Exit Next Summit Mark this and return
Answer:
Liquid
Explanation:
In most liquids the particles are less densely packed giving them the ability to move around and slide past each other.
Kevin used a pulley to lift a piano to the third floor of his apartment. His input work was 12,000 J and the output work was 10,000 J. What was the mechanical efficiency of the pulley?
A . 50%
B. 83.3%
C . 120%
D. 16.7%
Answer:
B
Explanation:
Eff = output work/input work ×100
Hence, Eff = 10000/12000 × 100
Eff = 83.3%
WhAT is the change IN THE entropy of 2.0kg of h2o molecules when transform at a constant pressure of 1 atm from water at 100 degrees celcius to steam at the same tEMPERATURE?
Answer:
The entropy change is 45.2 kJ/K.
Explanation:
mass of water at 100 C = 2 kg
Latent heat of vaporization, L = 2260 kJ/kg
Heat is
H = m L
H = 2 x 2260 = 4520 kJ
Entropy is given by
S = H/T = 4520/100 = 45.2 kJ/K
The entropy change during the phase change of water from liquids to steam at constant pressure and same temperatures will be zero because, Δ T is zero here.
What is entropy?Entropy is a thermodynamic parameter determining the measure of randomness in a system. Entropy of a natural reaction or change is always increasing.
According to second third law of thermodynamics the entropy change of the universe is positive always. At constant pressure the entropy change a of substance of m g is written as:
ΔS = m Cp ln T2/T1.
Where Cp is the specific heat capacity at constant pressure.
Here, the initial temperature and final temperature is same 100 degree celsius. Thus T2/T1 becomes 1 and log 1 is zero. Therefore, the entropy change in this phase change is zero.
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Pluto has a shape that is nearly round,and it orbits the sun,it has five known moons.why is it called a dwarf planet and not a planet?
There are three things needed to be classified as a planet.
Pluto meets 2 of the 3.
The one it does not meet is it doesn’t “clear the neighborhood” which means a planet needs to be gravitationally dominant over all objects around it. Meaning smaller bodies ( asteroids) would either combine with the larger body making it bigger or pushing them away ( out of their orbit) so they do not collide with the larger body.
Where are spores located on a fern? 1. On the root systems 2. In the flowers of the ferns 3. On the underside of the fronds 4. In the capsule of the sporophyte
un litro de un gas es calentado a presión constante desde 20°C hasta 60°C que volumen final ocupará dicho gas?
Answer:
Final volume, V2 = 3 Litres
Explanation:
Given the following data;
Initial volume, V1 = 1 litre
Initial temperature, T1 = 20°C
Final temperature, T2 = 60°C
To find the final volume, we would use Charles' law;
Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Charles is given by;
V1/T1 = V2/T2
Making V2 as the subject formula, we have;
V1T2 = V2T1
V2 = (V1T2)/T1
Substituting into the formula, we have;
V2 = (1 * 60)/20
V2 = 60/20
Final volume, V2 = 3 Litres
the direction of applied force has to be_____ to the distance in order to say work is done
Answer:
Explanation:
The direction of the applied force has to be parallel to the distance an object moved in order to say that work has been done.
the internal resistance of each of the following cells E1 and E2 shown in the figure above is 2ohms. calculate the total current in the circuit
Answer:
The total current in the circuit is 0.8 A.
Explanation:
internal resistance of each battery = 2 ohm
Total emf of the circuit, E = E1 + E2 = 2 = 2 = 4 V
Now total internal resistance is
[tex]r = \frac{2\times 2}{2 + 2}= 1 ohm[/tex]
Total resistance, R = 4 = 1 = 5 ohm
Let the current is I.
E = I R
4 = I x 5
I = 0.8 A
If the man pushes with a force of 2000N and friction is 500N, what is the resultant force?
Answer:
Explanation:
If the force of 2000 N is directed towards the right and the friction is directed towards the left, the 2000 N force is positive and the other is negative. To find the resultant force:
2000 - 500 = 1500 N to the right
Chiếu tia sáng lên một gương phẳng biết góc tới bằng 15⁰ hãy tính góc phản xạ bằng bao nhiêu
Answer:
góc phản xạ 15°
Explanatin
The particles of a substance stay close together but slide past one another as they move. When thermal energy is removed from the substance, the particles are forced into fixed positions by their attraction to one another. What change in state has occurred?
O A. Gas to solid
O B. Liquid to solid
O C. Solid to liquid
O D. Gas to liquid
Explanation:
The Answer is B.I think so may be it's wrong so kindly get any confirmation from your teacher about this
Uma pilha AA (pilha de controle remoto) fornece ao circuito 1,5V, já uma bateria de carro fornece 12V. Qual a relação entre a energia fornecida entre esses elementos de circuito?
Answer:
The ratio of energy of AA battery to the car battery is 0.0156.
Explanation:
An AA battery (remote control battery) supplies the circuit with 1.5V, while a car battery supplies 12V. What is the relationship between the energy supplied between these circuit elements?
Supply by AA battery = 1.5 V
Supply by car battery = 12 V
The resistance of the circuit is R.
The energy supplied = V^2/R
The energy supplied by the AA battery is
E = 1.5 x 1.5 / R = 2.25/R
The energy supplied by the car battery is
E' = 12 x 12/ R = 144 / R
So, the ratio of
E : E' = 2.25 : 144 = 0.0156
Which wave has the largest amplitude?
A.D
B.B
C.C
D.A
Answer:
D. A
General Formulas and Concepts:
Simple Harmonic Motion
Parts of a wave
PeriodAmplitudeWavelengthCrest/TroughExplanation:
The amplitude is the distance from the horizon to either the crest or trough of a wave.
In layman's terms, it is how high the wave is.
The "highest" wave would be wave A.
∴ our answer is D.
Topic: AP Physics 1 Algebra-Based
Unit: SMH
Answer:
A (The wave)
Explanation:
Wave A
5. According to the law of reflection, the
is equal to the angle of incidence and a line drawn perpendicular to the reflecting surface.
O reflected ray
angle of reflection
O angle of refraction
Answer:
the answer is ....angle of reflection
Firing a small rocket that starts at rest, the VMS-2 rises vertically under uniform acceleration, and in 50 seconds all the fuel is burned out. What is the maximum height at which the rocket rises?
Light of wavelength 530.00 nm is incident normally on a diffraction grating, and the first‑order maximum is observed to be 33.0∘ from the normal. How many slits per millimeter are marked on the grating?
Answer:
1028 slits/mm
Explanation:
We are given that
Wavelength of light, [tex]\lambda=530nm=530\times 10^{-9} m[/tex]
1nm=[tex]10^{-9} m[/tex]
[tex]\theta=33^{\circ}[/tex]
n=1
We have to find the number of slits per mm are marked on the grating.
We know that
[tex]dsin\theta=n\lambda[/tex]
Using the formula
[tex]dsin33^{\circ}=1\times 530\times 10^{-9}[/tex]
[tex]d=\frac{530\times 10^{-9}}{sin33^{\circ}}[/tex]
[tex]d=9.731\times 10^{-7} m[/tex]
1m=[tex]10^{3}mm[/tex]
[tex]d=9.731\times 10^{-7}\times 10^3[/tex]mm
[tex]d=0.0009731mm[/tex]
Number of slits=[tex]\frac{1}{d}[/tex]
Number of slits=[tex]\frac{1}{0.0009731}[/tex]/mm
Number of slits=1028/mm
Hence, 1028 slits/mm are marked on the grating.
Answer:
1027.6 lines per mm.
Explanation:
wavelength = 530 nm
order, m= 1
Angle = 33 degree
Let the slits per mm is 1/d.
So,
[tex]m \lambda = d sin A\\\\1\times 530\times 10^{-6} = d sin 33\\\\\frac{1}{d} = 1027.6 lines per mm[/tex]
What conditions can impact the ecological tolerance of a species?
Pls Answer,30 points
Answer:
climatic changes
ambient changes
human interferance and the growt of cities and human civilization
and invasive especies
Explanation:
Many different physical factors can impact the ecological tolerance of a species like:-
temperature humidity soil chemistry pHsalinity oxygen levelsHow physical factors impact the ecological tolerance of a species?Climatic factors such as temperature and precipitation are key drivers to control species distribution directly.Topographic features such as slope and elevation can impact local climate as well as soil conditions that in turn have varied effects on vegetation structure.The relative distance from a water source can also affect the composition and distribution of woody vegetation because of the resulting varying amount of water available for growth. Physical and chemical soil properties can inform vegetation patterns on a local scale.What is a tolerance range?The portion of the abiotic factor's range of variation which a species can survive and function in is commonly defined as the tolerance range.
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A stone is thrown vertically upwards with an initial velocity of 20m/sec. Find the maximum height ot reaches and the time taken by it to reach the height. (g=10m/s2)
plz short numerical ASAP
Answer:
The height reached is 20m, The time taken to reach 20m is 2 seconds
Explanation:
Observing the equations of motion we can see that the following equation will be most helpful for this question.
[tex]v^{2} = u^{2} + 2as[/tex]
We are given initial velocity, u
We know that the stone will stop at its maximum height, so final velocity, v
Acceleration, a
And we are looking for the displacement (height reached), s
Substitute the values we are given into the equation
[tex]0^{2} = 20^{2} + 2(10)s[/tex]
Rearrange for s
[tex]0^{2} -20^{2} =20s[/tex]
[tex]-400=20s[/tex]
[tex]\frac{-400}{20} =s[/tex]
s = -20 (The negative is just showing direction, it can be ignored for now)
The height reached is 20m
Use a different equation to find the time taken
[tex]s = vt - \frac{1}{2} at^{2}[/tex]
Substitute in the values we have
[tex]-20=(0)t - \frac{1}{2} (10)t^{2}[/tex]
Rearrange for t
[tex]-20 =0 -5 t^{2}[/tex]
[tex]\frac{-20}{-5} =t^{2}[/tex]
[tex]4 = t^{2}[/tex]
t = 2s
The time taken to reach 20m is 2 seconds
Which symbol and unit of measurement are used for electric current?
symbol. A, unit: 1
symbol: C, unit: A
symbol l; unit C
symbol: 1; unitA
Answer: Symbol is I and unit A
Explanation: A represents Amperes
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Imagine a landing craft approaching the surface of Callisto, one of Jupiter's moons. If the engine provides an upward force (thrust) of 3456 N, the craft descends at constant speed; if the engine provides only 2333 N, the craft accelerates downward at 0.39 m/s2. What is the weight of the landing craft in the vicinity of Callisto's surface
Answer:
[tex]W=3456 N[/tex]
Explanation:
Force 1 [tex]F_1=3456[/tex]
Force 2 [tex]F_2=2333N[/tex]
Acceleration at stage 2 [tex]a_2=0.39[/tex]
Generally the weight of the Craft W is given as
W= upward force(thrust)
Therefore
[tex]W=3456 N[/tex]
please answer me my question
Room heaters are placed on the floor of a room; Give reason:
Room heaters are placed on the floor of a room so that the air heated by it rises up and sets up the convection current in the room quickly and uniformly.
You are trying to hold your 550 g physics books with your hand against a vertical wall. Using a force sensor you know that the force you are applying is 10.0 N. Below the book on the floor you have placed a motion sensor. The position time graph for the book is given. Find the coefficient of kinetic friction.
The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is
∑ F = 10.0 N - n = 0
where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is
∑ F = f - (0.550 kg) g = 0
where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.
Then
• n = 10.0 N
• f = (0.550 kg) g = 5.39 N
• 5.39 N = µ (10.0 N)
==> µ = 0.539
Answer:
Above answer
Explanation:
The book's position is changing linearly with time, so its velocity is constant. This means that the net force acting on the book in the direction parallel to the surface is
∑ F = 10.0 N - n = 0
where n is the magnitude of the normal force on the book due to the wall, and the net force perpedicular to the surface is
∑ F = f - (0.550 kg) g = 0
where f is the mag. of kinetic friction, and f = µn where µ is the coefficient of kinetic friction.
Then
• n = 10.0 N
• f = (0.550 kg) g = 5.39 N
• 5.39 N = µ (10.0 N)
==> µ = 0.539
20 kg rodsis on the edge of a 80 m high de What is the rodes gracional potencial energy?
Answer:
Gpe = 15680 Joules
Explanation:
Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.
Mathematically, gravitational potential energy is given by the formula;
G.P.E = mgh
Where;
G.P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Given the following data;
Mass = 20 kg
Height = 80 m
We know that acceleration due to gravity is equal to 9.8 m/s²
To find the gravitational potential energy;
Gpe = mgh
Gpe = 20 * 80 * 9.8
Gpe = 15680 Joules
1.the student measures the mass of a piece of metal.its mass is 146g.
(a) the volume of the piece of metal is 20cmcube. calculate the density of the metal .
(b) state the unit.
Answer:
7.3 g/cubic cm
Explanation:
You divide the mass by the volume to calculate the density of the metal.
146g ÷ 20cm³ = 7.3g/cm³
An ice-skater with a mass of 80kg is holding a bowling ball with a mass of 8 kg. Suppose that the skater tosses the bowling ball forward with a speed of 6 m/s. What is the skater's reactive velocity? Show all work.
Answer:
0.6 m/s
Explanation:
The details of the masses and velocities are;
The mass of the ice skater, m₁ = 80 kg
The mass of the ball, m₂ = 8 kg
The speed with which the skater tosses the ball forward, v₂ = 6 m/s
Therefore;
According to the principle of conservation of linear momentum, we have;
m₁·v₁ = m₂·v₂
Where;
v₁ = The skater's reactive velocity
Therefore, we get;
80 kg × v₁ = 8 kg × 6 m/s
v₁ = 8 kg × 6 m/s/(80 kg) = 0.6 m/s
The skater's reactive velocity, v₁ = 0.6 m/s.
Which object has potential energy but not kinetic energy?

A.
A battery in a pair of headphones

B.
A person riding an elevator upward

C.
A person climbing a ladder

D.
A car that is slowing down
Answer:
A.
A battery in a pair of headphones
Explanation:
Potenial energy - the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
Earth changes all the time making it a __ planet.
What uses non-renewable energy?
A)a gematrical heating system
B)a nuclear power station
C)a solar panel
D)a wind turbine
