Answer:
-80 J
Explanation:
The first law of thermodynamics states that:
[tex]\Delta U = Q - W[/tex]
where
[tex]\Delta U[/tex] is the change in internal energy of the system
Q is the heat absorbed by the system
W is the work done by the system
In this problem, we have:
Q = -30 J is the heat released by the system (negative because the system releases it)
W = +50 J is the work done by the system on the surrounding (positive since it is done by the system)
Therefore, the change in internal energy is
[tex]\Delta U = -30 J - (+50 J) = -80 J[/tex]
Answer: -80 J
Explanation:
Need help with science questions!
If W = Fd, which describes the conditions that make the work of moving this 10 kg mass the easiest on the mover?
A.
Moving the mass from Point C to B, although it involves a greater distance, requires less force to do the same amount of work.
B.
Moving the mass from Point A to B involves a shorter distance to do the same amount of work, even though it requires more force.
C.
Moving the mass from Point C to B, although it involves a greater distance, requires less force and less work.
D.
Moving the mass from Point A to B involves a shorter distance so less work is done, even though it requires more force.
Answer:
A. Moving the mass from Point C to B, although it involves a greater distance, requires less force to do the same amount of work.
Explanation:
The amount of work will be the same either way. By going from C to B, the mover will exert less force over a greater distance, which is easier than exerting a greater force over a shorter distance.
The Doppler effect is the actual change in a star’s frequency of a wave.
True
False
The answer of this question maybe false
Answer:
False
Explanation: the Doppler effect is the
an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other.
One important way to adapt to diverse culture is to
Answer:
When people move from one culture to another they carry their background and culture with them, it is responsible for shaping their perception and adjustment to a new culture. Culture shock is a common experience for the people who have moved the new country or region, it includes confusion, shock, and disorientation. Extreme homesickness, avoiding social situations, physical complaints, and sleep difficulties are other symptoms of Cultural shock. However, there are strategies to deal with it. The strategies are to be open-minded and curious, using the observation skills and asking questions. By being open-minded you can change your values according to other cultures, by using your observation skills you can get a complete picture of what is going on in the new environment and by asking questions you can easily understand others and can make yourself understood.
Repeating your experiment _____. A. increases validity B. decreases validity C. has no effect on validity
Answer:
C. has no effect on validity
Explanation:
Repeating your experiment has no effect on validity.
It doesn't matter how many times you repeat your experiment. You have to find the average outcome of each experiment you do.
Earth has a mass of 5.97 x 10*kg, and a mean radius of 6.38 x 108m. What would be the orbital speed and period of a satellite in
orbit 1.44 x 109 m above Earth?
Explanation:
Centripetal acceleration = acceleration due to gravity
v² / r = GM / r²
Solving for velocity:
v = √(GM / r)
Given:
G = 6.67×10⁻¹¹ m³/kg/s²
M = 5.97×10²⁴ kg
r = 6.38×10⁸ m + 1.44×10⁹ m = 2.078×10⁹ m
v = √(6.67×10⁻¹¹ × 5.97×10²⁴ / 2.078×10⁹)
v = 438 m/s
Period is the time to travel one circumference:
T = 2πr / v
T = 2π (2.078×10⁹) / 438
T = 2.98×10⁷ s
T = 8290 hr
T = 345 days
A solid weighs 277.5 g in air and 212.5 g when totally immersed in the liquid of density 0.9 g/ cc. Calculate the density of the solid.
Answer:
3.842 g/cm³
Explanation:
Three forces are acting on the solid: weight, normal force (apparent weight), and buoyancy.
∑F = ma
N − m g + ρf V g = 0
N − ρs V g + ρf V g = 0
ρs is the density of the solid and ρf is the density of the fluid it is submerged in.
Writing normal force in terms of apparent mass, N = mₐ g:
mₐ g − ρs V g + ρf V g = 0
mₐ − ρs V + ρf V = 0
mₐ = ρs V − ρf V
mₐ = V (ρs − ρf)
V = mₐ / (ρs − ρf)
Volume is constant, so:
mₐ / (ρs − ρf) = mₐ / (ρs − ρf)
277.5 / (ρ − 0.0) = 212.5 / (ρ − 0.9)
Cross multiply and solve:
212.5ρ = 277.5 (ρ − 0.9)
212.5ρ = 277.5ρ − 249.75
249.75 = 65ρ
ρ = 3.842
The density of the solid is 3.842 g/cm³.
When Jacob bats a baseball with a net force of 4.719 N, it accelerates 33 m/s2. What is the mass of the baseball?
Answer:
Mass=0.143 kg
Explanation:
From the Newton's second law of motion the force applied to an object is directly proportional to the acceleration produced and the acceleration is in the direction of the force.
F=ma where F is the force, m is the mass of the object and a i the acceleration.
m=F/a
=4.719N/33 m/s²
=0.143 kg
A centrifuge is used to test space pilots. The centrifuge spins with a
centripetal acceleration of 6.55 g. If the length of the centrifuge's arm is 18 m,
what is the speed of the centrifuge?
Answer:
34 m/s
Explanation:
Centripetal acceleration is:
a = v² / r
Given a = 6.55 × 9.8 m/s² = 64.2 m/s², and r = 18 m:
64.2 m/s² = v² / (18 m)
v = 34 m/s
The speed of the centrifuge is 34 m/s.
Answer:
34 m/s
Explanation:
What type of force are you exerting when you stomp your foot on the ground
Final answer:
You exert a type of contact force called normal force when you stomp your foot on the ground, related to Newton's Third Law of Motion. While running or jogging, forces on the feet can be significantly greater, up to 2.5 times your body weight. The pressure results from your body mass, additional weight, and the surface area of the foot that makes contact.
Explanation:
When you stomp your foot on the ground, you are exerting a type of contact force known as a normal force. This action is governed by Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. Therefore, when your foot pushes against the ground, the ground pushes back with equal force. This force is a result of the pressure exerted by the stomp, which is a combination of the mass of your body and any additional weight you're carrying, and the surface area of your foot in contact with the ground.
When you're running or jogging, especially on hard surfaces or with insufficiently padded shoes, the forces on your feet and legs are significantly greater. They can be up to 2.5 times your body weight. This force can be calculated using the mass of the leg, the velocity at which it moves, and the distance over which it stops. Your own body weight also contributes to the force exerted on the ground during such activities. Proper foot arches help in absorbing this shock and reducing the impact on the rest of the body. When the downward motion of a runner's leg is stopped abruptly, the force required can be large and is impactful compared to the weight of the jogger.
which force keeps and object moving in a circle?
Answer:
Centripetal force
Explanation:
Centripetal force acts on an object moving in a circle. It points towards the center of the circle and has a magnitude equal to m v² / r, where m is the object's mass, v is the object's velocity, and r is the radius of curvature.
Engineers and others who work with technology use——————- to predict possible outcomes. A science. B peers. C bias. D by-products
Engineers and others who work with technology use science (A) to predict possible outcomes.
Answer:
A. science
Explanation:
Engineers and others who work with technology use science to predict possible outcomes.
They use predictions based on what the scientific research has shown them.
How much would a 50-kg object weigh on Mercury (gravity on Mercury is 3.59 m/s2)?
A. 13.9 N
B. 179.5 N
C. 310.5 N
D. 490.0 N
Answer:
B. 179.5 N
Explanation:
Weight is mass times acceleration due to gravity:
W = mg
W = (50 kg) (3.59 m/s²)
W = 179.5 N
Suppose a 1.2 m antenna is installed on top of a building that is 225 m tall,
What is the new total height of the building, including the antenna, expressed
with the correct number of significant figures?
Answer: 226.2 m
Explanation:
If we want to find the new total height [tex]H[/tex] of the building, we have to add to its initial height [tex]h_{B}=225m[/tex] the height of the antenna [tex]h_{A}=1.2m[/tex], as follows:
[tex]H=h_{B}+h_{A}[/tex]
[tex]H=225m+1.2m[/tex]
Then:
[tex]H=226.2m[/tex] This is the new total height of the building.
Guyz... Its my first question in this app... Pls do answer
Answer:
1.414
Explanation:
Snell's law states:
n₁ sin θ₁ = n₂ sin θ₂
where n is the index of refraction and θ is the angle of incidence (relative to the normal).
The index of refraction of air is approximately 1. So:
1 sin 45° = n sin 30°
n = sin 45° / sin 30°
n = 1.414
Round as needed.
During which two time intervals does the particle undergo equal displacement?
AB and BC
AB and EF
BC and DE
CD and DF
Answer:
BC and DE
Explanation:
In the given figure, the velocity time graph is shown. We know that the area under v-t curve gives the displacement of the particle.
Area under AB, [tex]d_1=\dfrac{1}{2}\times 2\times 10=10\ m[/tex]
Area under BC, [tex]d_2=\dfrac{1}{2}\times 2\times 4=4\ m[/tex]
Area under CD, [tex]d_3=\dfrac{1}{2}\times 2\times 7=7\ m[/tex]
Area under DE, [tex]d_4=\dfrac{1}{2}\times 2\times 4=4\ m[/tex]
Area under EF, [tex]d_5=\dfrac{1}{2}\times 2\times 3=3\ m[/tex]
So, form above calculations it is clear that, during BC and DE undergo equal displacement. Hence, the correct option is (c) "BC and DE = 4 meters".
Correct Answer:
AB & DE
Explanation:
I had just taken this test on Plato/Edmentum (physical science) and gotten the question correct
What did J.J Thomson experiments with cathode ray tubes imply about he mass of an electron?
Answer:
J.J. Thomson carried out an experiment in which he find the charge to mass ratio of electron.
Explanation:
J.J. Thomson carried out an experiment in which he used cathode rays which are emitted from cathode gun. Later it was proved that the cathode rays which are emitted from cathode gun were actually a beam of negatively charged particles which are known as electrons.
when these cathode rays passes through an electric field these rays get attracted towards the positively charged plate and get repelled by negatively charged plate of electric field. In this way these rays get deflected from its path and by measuring, how much cathode rays get deflected from its path J. J. Thomson was able to determine mass to charge ratio.
Thomson carried out the experiment by using different types of cathode which are made from different types of metal and he also filled different gases in the discharge tube but every time he got same charge to mass ratio. After repeating the experiment with different types of cathode and different gases, J.J. Thomson concluded that the cathode ray beam is actually consist of negatively charged particle which is a universal component of matter and which is known as electron. He observed that electron has fixed mass.
The density of some air at a pressure of 7720mmhg is 1.26kgm^-³. Determine its density at a pressure at 600mmHg?
Answer:
0.0979 kg/m³
Explanation:
Treating air as an ideal gas:
PV = nRT
n/V = P/RT
Density depends on both pressure and temperature. If we assume the temperature is constant, we can say that density is directly proportional to pressure.
ρ = kP
ρ/P = k
Writing a proportion:
(1.26 kg/m³) / (7720 mmHg) = ρ / (600 mmHg)
ρ = 0.0979 kg/m³
Answer:
[tex]\rho = 0.098 kg/m^3[/tex]
Explanation:
As we know that for ideal gas we will have
[tex]PV = nRT[/tex]
here we can convert it into the form of density
[tex]PV = \frac{m}{M}RT[/tex]
now we have
[tex]PM = \rho RT[/tex]
now if the temperature will remain constant then in that case
[tex]\frac{P}{\rho} = constant[/tex]
so we will have
[tex]\frac{P_1}{P_2} = \frac{\rho_1}{\rho_2}[/tex]
here we can plug in all values in it
[tex]\frac{7720}{600} = \frac{1.26}{\rho}[/tex]
now we have
[tex]\rho = \frac{600}{7720}(1.26)[/tex]
[tex]\rho = 0.098 kg/m^3[/tex]
During a storm, thunder is heared 7s after the lightining is seen. If the temperature of the air at the time of the storm is 28°C .how far away is the storm?
Answer:
2 meters
Explanation:
time is directly proportional to temperarure where distance is the constant k
therefore
T = t x 2a
28=7 x 2a
28= 14a
a=2m
Answer:
2440 m
Explanation:
The speed of light in air is approximately 3×10⁸ m/s.
The speed of sound in air at 28°C is approximately:
v = 331.4 m/s + 0.6 m/s/°C (28°C)
v = 348.2 m/s
Let's say the distance between you and the storm is x.
Distance = speed × time
x = 3×10⁸ t₁
x = 348.2 t₂
Since t₂ = t₁ + 7:
x / 348.2 = x / 3×10⁸ + 7
Solving for x:
x (1/348.2 − 1/(3×10⁸)) = 7
x = 2440
The storm is approximately 2440 meters away (round as needed).
In both the faraday and Henry experiments, a current was generated in the secondary coil by the phenomenon called ____?
Answer:
I think it's self inductance, but without knowing the options I'm not certain.
Answer:
induction
Explanation:
17. In which layer does mantle convection occur?
rms &
sources
LOGRAMS
A. Lithosphere
B. Inner core
C. Crust
• D. Asthenosphere
Answer:
D. Asthenosphere
Explanation:
The asthenosphere is relatively plastic part of the mantle which underlies the brittle lithosphere. In the asthenosphere, it is generally believed that the rocks are in ductile state and easily moves. It is the site of convection within the earth. In mantle convection, hot and light materials rises and keeps moving into upper crustal levels till they solidify. Here also, cold and denser materials sinks deeper till they turn to melt. This differences in temperature and density sets up a convective cell within the mantle. Several convective cells are in the mantle.
what is aerodynamics
Answer:
the branch of mechanics that deals with the motion of air and other gases and with the effects of such motion on bodies in the medium.Compare aerostatics(def 1).
Explanation:
Answer:
Aerodynamics is the way air moves around things.
As you drive down the road, you see and hear an ambulance go by you in the
opposite direction. After it passes, how is the frequency you hear different
from that being produced by the ambulance?
O
A. It is higher due to the Doppler effect.
B. It is lower due to the Doppler effect.
O
C. It has not changed, as the two vehicles cancel each othe_out.
O
D. It depends on which vehicle is moving the fastest.
Answer:
B. It is lower due to the Doppler effect.
Explanation:
According to the Doppler effect, observed frequencies are higher than the source frequency if the source is moving towards the observer, and lower if the source is moving away from the observer.
After the ambulance passes, it is moving away from you, so the frequency you hear is lower than the frequency at the ambulance.
Answer:
B. It is lower due to the Doppler effect.
Explanation:
A ball is launched from a cliff with and initial velocity of 15 m/s at an angle of 40 above horizontal. If the ball lands 17.5 m away, determine the height of the cliff.
Explanation:
Evaluate in the x direction to find the time it takes to land:
x = x₀ + v₀ₓ t + ½ aₓ t²
17.5 = 0 + (15 cos 40) t + ½ (0) t²
t = 1.52
Evaluate in the y direction to find the initial height:
y = y₀ + v₀ᵧ t + ½ g t²
0 = h + (15 sin 40) (1.52) + ½ (-9.8) (1.52)²
h = -3.32
The cliff is actually 3.32 meters below where it lands. Make sure you copied the problem correctly.
what is the answer to this question I don't know it
Answer:
B
Explanation:
The apple is less dense than the water but not enough so to float with the least amount of apple submerged
Answer: Option B
Explanation: First, density is defined as mass/volume, so for two objects with the same volume, the more dense one has more weight.
Here we see that the apple is less dense than the water, which means that the water is heavier than the apple.
This means that only a tiny part of the apple will be submerged in the water (where the displaced water/profundity of the apple depends on the size of the apple, the displaced water must have the same weight than the apple, in that point the forces are canceled a the apple will be at rest)
The correct option is B
Average velocity is different than average speed because calculating average velocity involves .
Average speed is total distance traveled divided by time. It is a scalar quantity (just magnitude).
Average velocity is displacement divided by time. It is a vector quantity (magnitude and direction).
An average velocity is different from average speed as average velocity is calculated using total displacement and total time into consideration.
Explanation:
The average velocity is calculated using the total displacement and total time, whereas the average speed is calculated using the total distance and total time.
“Average velocity is a vector quantity” and thus takes the magnitude and direction of vector displacement in calculation. Average speed is scalar quantity.
[tex]\text {Average velocity}=\frac{\text {Total displacement}}{\text {Total time}}[/tex]
Which types of electromagnetic waves have higher frequencies than the waves that make up ultraviolet light? Check all that apply
Answer:
X-rays
Gamma rays
Explanation:
The electromagnetic waves are arranged in order of their frequencies and wavelengths. This arrangement forms the electromagnetic spectrum. The x-rays and gamma rays form the part of the spectrum with highest frequencies and least wavelength. In the order of decreasing frequency and increasing wavelength, we start with Gamma rays ,x-rays uv, Visible light, Infrared light,Microwave then radio waves.
Answer:
X rays and Gamma rays.
Explanation:
The electromagnetic waves are arranged in the increasing frequency and energy while decreasing wavelength. So the waves on the right side of ultraviolet spectrum having higher frequency and energy and lower wave length. such as X RAYS AND GAMMA RAYS. Electromagnetic wave spectrum is arranged as.
Radio waves, microwaves, infrared waves, visible rays, ultraviolet waves, x rays, gamma rays.
Select the sources of tax revenue for federal, state, and local governments. Select all that apply.
personal income
sales
payroll
education
Explanation:
The sources of tax revenue for federal,state and local government is personal income ,payroll and sales.
Government take some taxes if the income of person is beyond a specified limit.That limit is specified by government itself.
Government also take some taxes from sales product.
When public or enterprises pay payment online then government take some taxes.
Do quasars reside within or without side of galaxies?
They almost entirely reside within galaxies because quasars are a subset of blackholes with a large and fast enough accretion disk to generate a beam of interstellar material perpendicular to itself. This typically only occurs in the largest black holes at the center of galaxies (supermassive blackholes) or at least stellar black holes---which still occur within galaxies because the material is necessary to form them.
Which is a chemical change?
A. Splitting water into hydrogen and oxygen.
B. Breaking a block of solid ice into smaller pieces.
C. Freezing liquid water.
D. Boiling Water
Answer:
A. Splitting water into hydrogen and oxygen.
Explanation:
A chemical change produces a new substance. ... A physical change does not produce a new substance. Changes in state or phase (melting, freezing, vaporization, condensation, sublimation) are physical changes.
Splitting water into hydrogen and oxygen.
when two equal forces act on the same object in opposite directions, what is the net force?
Answer:
0
Explanation:
Forces with equal magnitudes and opposite directions cancel each other out, so the net force is 0.
Answer:
0
Explanation:
when you try to give two equal force on object in opposite side, the object will not move.hence the net force will be zero
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