The Universe is often studied by Scientist. The primary form of evidence that has led astronomers to conclude that the expansion of the universe is accelerating is the Observations of white dwarf supernovae.
There was the discovery of the faintness of high-redshift Type I supernovae by a team of scientist which showed that the expansion of the universe is accelerating.
The key evidence for that made scientist to talk about the expansion of the universe is accelerating comes from viewing and studying of white dwarf supernovae. It has been found that most distant stars all orbit at approximate speed as stars found about 30,000 light-years from their center.
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Explain why the temperature is not changing at X
Answer:
The temperature is constant at 'X'. No increase or decrease. Would be same answer if there were a 'X' at temperature 'D'.
Slope of graph is zero so no change in the temperature.
What is temperature?
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer.
Given graph of temperature and time, at position x there in no change in temperature with time so temperature is not changing.
Slope of graph is zero so no change in the temperature.
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A 2.55 kg piece of lead at 40 degree Celsius is placed in a very large quantity of water at 10 degree Celsius and thermal equilibrium is eventually reached. Calculate the entropy change of the lead that occurs during this process. The specific heat of lead is 130 J/(kg K).
6.6 J/K
1.4 J/K
190 J/K
100 J/K
6.2 J/k
i think this is a answer
A 2 kg object being pulled across the floor with a speed of 10 m/sec is suddenly
released and slides to rest in 5 sec. What is the magnitude of the frictional force
producing this deceleration?
Answer:
The frictional force producing this deceleration would have a magnitude of [tex]4\; \rm N[/tex].
Explanation:
The velocity of this object changed by [tex]\Delta v = (-10\; \rm m\cdot s^{-1})[/tex] in [tex]\Delta t = 5\; \rm s[/tex]. The acceleration of this object would be:
[tex]\begin{aligned}a &= \frac{\Delta v}{\Delta t} \\ &= \frac{-10\; \rm m\cdot s^{-1}}{5\; \rm s} = -2\; \rm m\cdot s^{-2}\end{aligned}[/tex].
Let [tex]m[/tex] denote the mass of this object. By Newton's Second Law of Motion, the net force on this object would be:
[tex]\begin{aligned}F &= m \, a \\ &= 2\; \rm kg \times (-2\; \rm m\cdot s^{-2}) \\ &= -4\; \rm N\end{aligned}[/tex].
([tex]1\; {\rm kg \cdot m \cdot s^{-2} = 1\; {\rm N}[/tex].)
If the floor is level, friction would be the only unbalanced force on this object. Thus, the magnitude of the frictional force on this object would also be [tex]4\; {\rm N}[/tex], same as the magnitude of the net force on this object.
"A soccer ball is kicked horizontally off a 22 m high hill and lands a distance of 35 m from the edge of the hill." Which variable is 35 m? *
Answer:Let’s assume that, after the soccer ball is kicked and moves through its trajectory, it first makes contact with level ground a horizontal distance of 35 meters from where it was kicked. Let’s also assume that we can neglect air resistance. The time, t, that the soccer ball is in the air until it first contacts the ground can be found from the equation h = (1/2)gt^2 which can be rewritten as t = sqrt(2h/g) where h is the vertical distance the ball falls which is the height of the hill since the ball was kicked horizontally, and g is the acceleration of gravity which is 9.8 m/s^2. So t = sqrt(2(22)/9.8) = 2.12 seconds. In that time, the ball travelled 35 meters so its horizontal velocity was 35 meters/2.12 seconds = 16.5 meters/second.
Explanation:
which one would cool down faster, water or a block of concrete? why?
Answer:
If you mean by temperature
Water, cause say the water just sits there, it'll take a few minutes to cool down. But for concrete having all the hot sun rays on it during summer, can make it very hot, if you put 'cold water' there, it'll only last there for a moments (and that's by effect not waiting), if you wait for it to cooldown by itself, it'll take quite awhile.
If you mean solidify:
The stuff required to make concretes takes HOURS and HOURS to finish solidifying, unlike water being turn into ice normally only takes about half an hour or an hour (maybe 2) in the freezer (I don't know how long for ice, but not long at all in comparison to concrete).
Explanation:
Explanation was mostly part of the answer
what is the force that every mass experts on every other mass called?
Answer: The forces of gravity
Explanation: The consequence of this phenomenon is that every mass exerts a so-called "force of mutual attraction" on every other mass. The attractive force that the celestial bodies exert on other masses by virtue of their total mass is called the force of gravity.
Hope this helps
at room tmeperature none of the metals are
What metal is not at room temperature?
Mercury is a metallic chemical element that is an only metal that is not a solid at room temperature.
A roll of kitchen aluminum foil is 30 cm wide by 22 m long (if you unroll it). If the foil is 0.15 mm thick, and the specific weight of aluminum is 26460 N/m3, how much does the roll of aluminum foil weigh
The weight of the aluminum foil is 26.20 N
To find the weight of the aluminum foil when it is unrolled, we need to find its volume.
The volume V = lwt where
l = length of aluminum foil = 22 m, w = width of aluminum foil = 30 cm = 0.30 m and t = thickness of aluminum foil = 0.15 mm = 0.15 × 10⁻³ m.So, V = lwt
= 22 m × 0.30 m × 0.15 × 10⁻³ m
= 0.99 × 10⁻³ m³.
So, its weight W = ρV where
ρ = specific weight of aluminum = 26460 N/m³ and V = volume of aluminum foil = 0.99 × 10⁻³ m³So, W = ρV
W = 26460 N/m³ × 0.99 × 10⁻³ m³
W = 26195.4 × 10⁻³ N
W = 26.1954 N
W ≅ 26.20 N
So, the weight of the aluminum foil is 26.20 N
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You are on the roof of a building 30 m above the ground. Using hand crank 3 points
you are to lift a 300 kg dresser on to the roof. How much work must to
generated to lift the dresser? *
Answer:
The work will increase the potential energy.
W = PE = mgh = 300(9.8)(30) = 88200 J
True or False If the mass of the object increases, then the potential energy of the object decreases.
The vertical and horizontal components of the velocity of a golf ball after being struck by a club are 4.0 m s1 and 5.0 m s respectively. Determine the magnitude and direction of the velocity of the golf ball. A 6.30 m s-1 B 6.35 m s-1 C 6.40 m s-1 D 6.45 m 5-1
The magnitude and direction of the velocity of the golf ball is 6.4 m/s at 38.7⁰.
The given parameters:
Vertical component of the velocity, [tex]v_y = 4 \ m/s[/tex]Horizontal component of the velocity, [tex]v_x = 5 \ m/s[/tex]The magnitude of the resultant velocity of the golf ball is calculated as follows;
[tex]v= \sqrt{v_y^2 + v_x^2} \\\\v = \sqrt{4^2 + 5^2} \\\\v = 6.4 \ m/s[/tex]
The direction of the golf ball's velocity is calculated as follows;
[tex]\theta = tan^{-1} (\frac{v_y}{v_x} )\\\\\theta = tan^{-1}(\frac{4}{5} )\\\\\theta = 38.7 \ ^0[/tex]
Thus, the magnitude and direction of the velocity of the golf ball is 6.4 m/s at 38.7⁰.
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a 4kg sample of water absorbs 500 joules of energy.How much did the water temp change.The specific heat of water is 4200 J/(kg C)
Answer:
0.02976°C
Explanation:
Heat Supplied = mcø
ø = 500/(4*4200)
ø = 0.02976 °C
What does water’s high specific heat capacity explain about water?(1 point)
why water bonds with other molecules
why water bonds with other molecules
why water is unable to absorb energy
why water is unable to absorb energy
why water is liquid at room temperature
why water is liquid at room temperature
why water is often used as a solvent
Water’s high specific heat capacity explain why water is liquid at room temperature
option C is the correct answer.
What is specific heat capacity?
The specific heat capacity of an object is the amount of heat required to raise the temperature of a unit mass of the substance by 1 kelvin.
The relationship between specific heat capacity and heat capacity of a substance is given as;
c = Q/mΔθ
where;
Q is the quantity of heat c is the specific heat capacitym is the mass of the substanceΔθ is the change in temperatureA high specific heat capacity implies that the substance absorbs more energy to change its state.
Thus, water has a high specific heat, meaning it takes more energy to increase the temperature of water compared to other substances. When water absorb more heat energy, it changes its state.
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One potato plant makes 7.5
potatoes. There are 10.000
people on a ship and 3
potatoes per person. How
many potato plants are
needed per person.
If all conditions are ideal, you may harvest about five to 10 potatoes per plant for your gardening efforts. Yields are based on both the care your give your plants during the growing season and the variety of potatoes you choose to grow.
answer
7.5×10.000=75÷3=25
Use the periodic table to answer the question.
An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods).
Which comparison is correct?
(1 point)
PH3 is a stronger acid than NH3.
PH, 3, is a stronger acid than NH, 3, .
HF is a stronger acid than HCl.
HF is a stronger acid than HCl.
H2S is a stronger acid than HCl.
H, 2, S is a stronger acid than HCl.
NH3 is a stronger acid than HF.
Answer:
A: P and N are both nonmetals, same strength: No
B: Most likely not
C: Same saying as B
D: Most likely yes
Explanation:
I don't actually know if i'm right, I just want to help you okay, so if it's wrong than sorry. Also I couldn't tell if the CI is a Ci(17) or CL(6+53)
Part reason why I was saying that B and C are most likely incorrect. And D the NH3 has more value than HF (if I remember)
As per the given situation, [tex]PH_3[/tex] is stronger acid than [tex]NH_3[/tex]. The correct option is A.
What is an acid?Any substance that tastes sour in water, turns blue litmus paper red, reacts with some metals to liberate hydrogen, reacts with bases to form salts, and promotes chemical reactions is considered an acid (acid catalysis).
Because strong acids have mostly ions in solution, the bonds that hold H and A together must be weak. Strong acids easily dissociate into ions.
Because weak acids exist primarily as molecules with only a few ions in solution, the bonds that hold H and A together must be strong.
[tex]PH_3[/tex] is a more potent acid than [tex]NH_3[/tex]. as PH3 has a pKa of -5.5 and [tex]NH_3[/tex] has a pKa of 9.9.
Thus, the correct option is A.
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A child on ice skates is given a small push from behind by a parent. How are forces used to describe the resulting motion?(1 point)
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move.
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move.
There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
There is a balanced force on the child, and the child’s motion will change direction or increase speed.
There is a balanced force on the child, and the child’s motion will change direction or increase speed.
Because of equal and opposite reactions, the child will move in the opposite direction to the force.
A child on ice skates is given a small push from behind by a parent. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
A child on ice skates is given a small push from behind by a parent. How are forces used to describe the resulting motion?
Because of equal and opposite reactions, there will be a force opposing the push from the parent, and they will not move. FALSE. According to Newton's third law of motion, if the parent applies force on the child, there will be a reaction applied by the child on the parent. These forces are applied to different objects so they will not cancel and the child will move. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed. TRUE. The child will have an acceleration as a consequence of the unbalanced force. The acceleration will be responsible for the change in the direction or speed of the child. There is a balanced force on the child, and the child’s motion will change direction or increase speed. FALSE. If the forces were balanced, that is, there was no net force, the movement of the child would not change, as stated by Newton's first law of motion. Because of equal and opposite reactions, the child will move in the opposite direction to the force. FALSE. The child will move in the direction of the net force.A child on ice skates is given a small push from behind by a parent. There is an unbalanced force on the child, and the child’s motion will change direction or increase speed.
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Hey there!
having a question which is from ( JEE Advanced 2014 )
[tex]\huge\color{black}\boxed{\colorbox{pink}{Question♡}}[/tex]
A rocket is moving in a gravity free space with a constant acceleration of 2 −2 along +x direction (see figure). The length of a chamber inside the rocket is 4 m. A ball is thrown from the left end of the chamber in +x direction with a speed of 0.3 −1 relative to the rocket. At the same time, another ball is thrown in –x direction with a speed of 0.2 −1 from its right end relative to the rocket. The time in seconds when the two balls hit each other is?
[tex] \\ \\ [/tex]
proper explanation needed~
thankyou~
The time taken for the two balls to hit each other is 8 s.
The given parameters:
Acceleration of the rocket, a = 2 m/s²Length of the chamber, s = 4 mSpeed of the first ball, = V1 = 0.3 m/sSpeed of the second ball, V2 = 0.2 m/sThe time taken for the two balls to hit each other is calculated by applying relative velocity formula as shown below;
[tex](V_1 - (-V_2) )t = s\\\\(V_1 + V_2) t = s\\\\(0.3 + 0.2) t = 4\\\\0.5t = 4\\\\t = \frac{4}{0.5} \\\\t = 8 \ s[/tex]
Thus, the time taken for the two balls to hit each other is 8 s.
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How do I measure the drag of a paper airplane?
Answer:
hmmmmm ill get back later
Explanation:
Based on the law of conservation of mass, if approximately 20g of water reacts in the following equation,
producing about 15g of oxygen, what mass of hydrogen (H2) was produced in this reaction?
2H20
2H2 + O2
Answer: H2O2
Explanation:
First, calculate the moles of H2O2 reacting. In order to do this, we must evaluate the relative molecular mass ( Mr ) of hydrogen peroxide
3. a car takes off with initial velocity of 20m/s and move with uniform acceleration of 12m/s2 for 20s. It maintained a constant velocity for 30s and come to rest with uniform acceleration of 2m/s2. Calculate the total distance covered by the car.
The total distance traveled by the car at the given velocity and time is 900 m.
The given parameters:
initial velocity of the car, u = 20 m/sacceleration of the car, a = 12 m/s²time of motion of the car, t = 20 sfinal time = 30 sfinal acceleration = 2 m/s²The final time of motion of car before coming to rest is calculated as follows;
[tex]v_f = v_0 -at\\\\0 = 20 - 2t\\\\t = 10 \ s[/tex]
The graph of the car's motion is in the image uploaded.
The total distance traveled by the car is calculated as follows;
[tex]total \ distance = A \ + B \ + C\\\\total \ distance = (\frac{1 }{2} \times 20 \times 20) \ + (20 \times 30) \ + (\frac{1}{2}\times 10 \times 20)\\\\total \ distance = 900 \ m[/tex]
Thus, the total distance traveled by the car at the given velocity and time is 900 m.
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a heat engine is a device that uses to produce useful work
A heat engine is a device that uses to produce useful work.
Definition - a device for producing motive power from heat, such as a gasoline engine or steam engine.
So..
If this is a true or false question.. Your answer is:
TRUE
Answer:
HEAT
Explanation:
A student catches a can of soda dropped from some unknown height by Mr. Fineman. If
the can was dropped from rest, and it is traveling at 8.9 m/s before it arrives in the
student's hand...
Answer:
v² = u² + 2gh
8.9² = 0² + 2(9.8)h
h = 4.0 m
v = at
t = 8.9/9.8
t = 0.91 s
Two a.c V1=100sin(wt) and V2 = 150cos(wt) are fed into one circuit, determine the combined output of the two as a single a.c
Answer:
Explanation:
V = 100sin(ωt) + 150cos(ωt)
let x = ωt
V = 100sin(x) + 150cos(x)
a maximum or minimum will occur when the derivative is zero
V' = 100cos(x) - 150sin(x)
0 = 100cos(x) - 150sin(x)
100cos(x) = 150sin(x)
100/150 = sin(x)/cos(x)
0.6667 = tan(x)
x = 0.588 rad
V = 100sin(0.588) + 150cos(0.588)
V = 180.27756
as the maximum will not occur until ωt = 0.588 radians, for a cosine function we subtract that amount as a phase angle φ
V = 180.3 cos(ωt - 0.588)
or as a sine function, the phase angle lags the cosine by a difference of π/2
V = 180.3sin(ωt - (0.588 - π/2)
V = 180.3sin(ωt + 0.983)
Where do inherited traits come from
Answer:
Your parents or anyone in your ancestry.
Explanation:
An object is projected with speed of 4ms at an angle of 60° to horizontal. Calculate the time of flight of the object. (g=10ms2)
0.8 seconds
Explanation:
time of flight = 2u/g
u=4m/s
g=10
= 8/10
= 0.8 sec
just a trial...not sure!!!
Given :
∅ = 60⁰
u = 4 m/s
g = 10m/s²
to find :
T = ?
Solution :
as per formula,
[tex]t = \frac{2u \: sin \theta}{g} [/tex]
now put the value : [tex]t \: = \frac{2 \times 4 \times sin \: 60}{10} [/tex]
as we know [tex] sin60 \: = \frac{ \sqrt{3} }{2} [/tex]
therefore,
[tex]t \: = \frac{8 \times \frac{ \sqrt{3} }{2} }{10} [/tex]
as we solve this we get,
[tex]t \: = \frac{ 2\sqrt{3} }{5} [/tex]
that's t = 0.69 sec
[tex]\sf\fbox\red{\:I \:hope \:it's \:helpful \:to \:you}[/tex]
PLEASE ANSWER THIS, I'LL MARK YOU AS BRAINLIEST
Carlito was observing an an that crawled along a table. With a piece of chalk, he followed his path. He determined the ant’s displacements by using a ruler and protractor. The displacements were as follows: 2 cm east, 3.5 cm, 32° north of east and 2.4 cm, 22° west of north. Find the resultant vector using graphical method.
Answer:
this is the answer
Explanation:
hope it's clear
pls Mark me as the brainliest pls
When laser light of wavelength 632.8 nm passes through a diffraction grating, the first bright spots occur at ± 17.8 ∘ from the central maximum. What is the line density
Answer:
Depends on the weight i would be 7.120
During what time period does the balloon drift in a counterclockwise direction?
You will create your own circuit , discuss how electricity flows and describe how circuits are made in
Answer:
An electric current flows in a loop,powering bulbs or other electric COMPONENTS. The loop is an electric circuit. A circuit is made up of various components linked together by wires. The current is driven around the circuit by a power source, such as a BATTERY.
Voltage: is the energy given to each unit of charge that flows in a circuit
Current: is the amount of electric charge flowing past a point in a circuit each second
Wattage: is the amount of electrical energy a circuit uses each second
7. What is the velocity of an object with a distance of 90m south and a time of
5s?
Answer:
Explanation:
v= s/t
V =90m/5s
V = 8m/s