The expansion joints in a concrete bridge allow for thermal expansion, preventing buckling by accommodating changes in size due to temperature variation. This allows the bridge to withstand frequent temperature changes without significant structural damage.
Explanation:The subject of this question involves a phenomenon known as thermal expansion, which is a concept in physics. When the temperature of a material changes, the material can expand or contract. Concrete, like many other materials, expands when heated and contracts when cooled.
On a sunny day, especially a very hot one like 115 degrees Fahrenheit, the heat from the sun causes the concrete slabs in the bridge to expand. Thanks to the expansion joints between the slabs, the bridge can change length without buckling under this thermal stress. The expansion joints are designed to accommodate this precise thermal expansion, allowing the slabs to expand and contract freely with changes in temperature.
In the case of the Auckland Harbour Bridge in New Zealand, the bridge is equipped with thermal expansion joints that prevent it from buckling due to thermal expansion. Similarly, the change in length of the bridge due to temperature changes is usually small and distributed across multiple expansion joints, making the process almost unnoticeable in daily use.
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to cook food in the microwave oven converts electrical energy into. energy. a. electricmagnetic. b. heat. c. mechanical d.nulcleae
A 616 g block is released from rest at height h0 above a vertical spring with spring constant k = 540 n/m and negligible mass. the block sticks to the spring and momentarily stops after compressing the spring 23.3 cm. how much work is done (a) by the block on the spring and (b) by the spring on the block? (c) what is the value of h0? (d) if the block were released from height 2h0 above the spring, what would be the maximum compression of the spring?
A rotating fan completes 1100 revolutions every minute. consider a point on the tip of a blade, at a radius of 0.18 m. through what distance does the point move in one revolution?
An 80 N force has been applied to a block and move it 20m along the direction of the force.
Calculate the momentum of a 953kg elephant running at a rate of 3.85 m/s.
The period of a mechanical wave is 4 seconds. What is the frequency of the wave? 8.0 waves/second 4.0 waves/second 0.25 waves/second depends on the speed of the wave
Hello!
Data:
T (period) = 4 s
f (frequency) = ? (waves/second)
Formula:
[tex]f = \dfrac{1}{T}[/tex]
Solving:
[tex]f = \dfrac{1}{T}[/tex]
[tex]f = \dfrac{1}{4}[/tex]
[tex]\boxed{\boxed{f = 0.25\:waves/second}}\end{array}}\qquad\quad\checkmark[/tex]
___________________________
I Hope this helps, greetings ... Dexteright02! =)
What vibrates when an aeroplane flies over our house?
After watching an advertisement for hand sanitizer on television, Ben decided to see just how effective the advertised hand sanitizer really was. Ben used warm water as his control. He compared the advertised sanitizer with two brands of hand soap. In all four trials he rubbed his hands together for two minutes. After using the three products and the control, he cultured the bacteria on his hands. He recorded the number of bacterial cultures that appeared on each culture plate. Ben's results can be seen in the data table. Ben concluded that both brands of soap were more effective in killing bacteria than the advertised hand sanitizer. What term BEST describes Ben's results for all four trials? A) biased B) inconclusive C) qualitative D) quantitative ASAPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP
Answer:
answer is quantitive this guy is wrong
Explanation:
did it on usatestprep
A completely ionized beryllium atom (net charge = +4e) is accelerated through a potential difference of 6.0 v. what is the increase in kinetic energy of the atom?
Final answer:
The increase in kinetic energy of a completely ionized beryllium atom accelerated through a potential difference of 6.0 V is +24 electron volts (eV).
Explanation:
To calculate the increase in kinetic energy of a completely ionized beryllium atom accelerated through a potential difference of 6.0 V, we need to use the formula:
ΔK = q × ΔV
Where ΔK is the increase in kinetic energy, q is the charge of the ion, and ΔV is the potential difference. In this case, the beryllium atom is completely ionized with a net charge of +4e, where e is the elementary charge. Therefore, the charge (q) is +4e.
Substituting the values, ΔK = (+4e) × (6.0 V) = +24eV
So, the increase in kinetic energy of the atom is +24 electron volts (eV).
The water cycle is a biogeochemical cycle that is a closed system. Which of these sentences describes a viable stage that occurs in the water cycle?
(A)Water enters and exits the system boundaries of the cycle.
(B)Water can change from solid to liquid at certain points in the cycle.
(C)Ice forms anew, adding matter to the cycle.
(D)Water vapor condenses, subtracting energy from the cycle.
Answer:
b
Explanation:
The water cycle is a biogeochemical cycle that is a closed system. the statement describes a viable stage that occur in water cycle is that water can change from solid to liquid at certain points in the cycle. therefore the correct answer is option B.
What is hydropower?A dam or other construction that alters the natural flow of a river or other body of water is used to generate hydropower, often known as hydroelectric power.
Hydropower utilizes the endless water cycle, which uses water as fuel and produces no waste products, to produce electricity. Hydropower plants come in a variety of shapes and sizes, but they are always constantly pushed by the kinetic energy of water going downstream.
In a closed system, the water cycle is a biogeochemical cycle. The fact that water can transform from solid to liquid at specific periods during the cycle is described in the phrase as a possible stage that occurs in the water cycle.
Thus, the correct answer is option B.
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A tennis ball is thrown from ground level with velocity directed 30° above the horizontal. if it takes the ball 0.5 s to reach the top of its trajectory, what is the magnitude of the initial velocity?
Using the equation of motion v = u + gt and knowing that at the top of its trajectory the final velocity of the ball is 0, the time it takes to reach there is 0.5 seconds and the acceleration due to gravity is -9.8 m/s², we can determine the magnitude of the initial vertical component of the velocity to be 4.9 m/s. As the ball was thrown at a 30° angle, this means the magnitude of the initial velocity is 9.8 m/s.
Explanation:In order to find the initial velocity of a projectile, we can use a foundational equation from Physics. Specifically, the formula v = u + gt where v is the final velocity, u is the initial velocity, g is acceleration due to gravity, and t is time. We're told that the ball takes 0.5 seconds to reach the top of its trajectory. At the top of its trajectory, the ball's final velocity will be 0 m/s (because it momentarily stops before falling back down). Also, the acceleration due to gravity is -9.8 m/s². Re-arranging the formula to solve for u gives us u = v - gt. Replacing v with 0, g with -9.8 m/s², and t with 0.5 s gives u = 0 - (-9.8 m/s² * 0.5s) = 4.9 m/s. However, this 4.9 m/s is just the vertical component of the initial velocity, because gravity acts vertically. Since the balls is thrown at an angle of 30°, to get the magnitude of the initial velocity, we have to divide 4.9 m/s by sin(30°) which gives us roughly 9.8 m/s. Therefore, the magnitude of the initial velocity is approximately 9.8 m/s.
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Consider the vector b⃗ with magnitude 4.00 m at an angle 23.5∘ north of east. what is the x component bx of this vector? express your answer in meters to three significant figures.
El Sol está en promedio a 93 millones de millas de la Tierra. ¿A cuántos metros equivale esto? Expréselo usando potencias de diez.
La distancia promedio entre la Tierra y el Sol es de aproximadamente 93 millones de millas. En metros, esta distancia es de aproximadamente 1.5*10^11. Se utiliza la notación científica 1.5 × 10¹¹ metros para representar esta distancia de forma más concisa y manejable.
Explanation:El Sol está, en promedio, a 93 millones de millas de la Tierra. Sabemos que 1 milla equivale a 1.60934 kilómetros y que un kilómetro es igual a 10^3 metros. Por lo tanto, podemos decir que una milla es igual a 1.60934*10^3 metros.
Para convertir la distancia desde la Tierra hasta el Sol a metros, multiplicamos 93,000,000 millas por 1.60934*10^3 metros/milla. Esto da como resultado aproximadamente 1.5*10^11 metros. Así que, en notación científica, la distancia desde la Tierra hasta el Sol es de aproximadamente 1.5 × 10¹¹ metros.
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How much work does the electric field do in moving a proton from a point with a potential of +125 v to a point where it is -55 v? express your answer both in joules and electron volts?
The work done by the electric field in moving a proton from +125V to -55V is -expressed as -180 electron volts (eV).
Using the relationship between work (W), charge (q), and electric potential difference (V).
The charge of a proton is +1.602 × 10^-19 coulombs (elementary charge, e), and the potential difference
V is the final potential minus the initial potential.
So, we compute the potential difference first:
V = V_final - V_initial = (-55V) - (+125V) = -180V
Then, we calculate the work done:
W = q
V = (1.602
10^-19 C)
(-180 V) = -2.8836
10^-17 joules
The negative sign indicates that the electric field is doing work against the electric potential. To express the work in electron volts, remember that 1 eV = 1.602
10^-19 joules:
W (in eV) = W (in joules) / (1.602
10^-19 joules/eV)
= (-2.8836
10^-17 joules) / (1.602
10^-19 joules/eV) = -180 eV
Bob is studying waves in science and learns that the energy of a wave is directly proportional to the square of the waves amplitude. If the amplitude of a wave changes from 2m to 1m, what should he predict as the effect on energy of the wave? A) The energy is halved. B) The energy is doubled. C) The energy is quartered. D) The energy is quadrupled.
Answer:
It's C
Explanation:
Since E ∝ amplitude2 then as the amplitude is halved the energy is quartered.
Plugging in to check
amplitude2=E
22=4
12=1
Match the cloud type with its description.
1.
cumulus
resembles an overcast sky; layers of gray or white clouds
2.
altostratus
clouds nearest Earth's surface
3.
cirrus
look like wispy feathers high in the sky
4.
nimbostratus
dark, thick-layered clouds; rain's coming
5.
fog
look like pieces of cotton in the sky
A circuit contains a single 270-pf capacitor hooked across a battery. it is desired to store four times as much energy in a combination of two capacitors by adding a single capacitor to this one. what would this value be
which theory of plate movements involves magma rising all the way from the lower mantle to spread apart plates
Answer:
hot plumes
Explanation:
Marta, Cato, and Juan plan a skit to illustrate one of the methods of charging.
Marta and Cato are walking together. Each has one flower and one box of candy.
Juan offers Cato a huge bouquet of flowers, but Cato can’t take it because his hands are full.
Cato hands his flower to Marta and then turns to Juan to take the bouquet.
Marta walks away in one direction with two flowers and one box of candy. Juan keeps the bouquet and walks away in the other direction. Cato looks sad standing alone with only a box of candy.
How does the skit model a method of charging?
a It models induction because an electron (a flower) transfers from Cato to Marta through direct contact.
b It models friction because an electron (a flower) transfers from Cato to Marta through direct contact.
c It models friction because the offer of flowers represents a charged object that causes an electron (a flower) to transfer from one object to another.
d It models induction because the offer of flowers represents a charged object that causes an electron (a flower) to transfer from one object to another.
The answer is C. Frictional charging is primarily involved. In the scenario, the bouquet of flowers represents a charged object that causes an electron (or the flower) to transfer from one object to another. Due to the bouquet of flowers, the other flower repelled and moved towards the object with a lesser charge. As a result, the box becomes neutral or has no charge at all.
The answer is D.
I just took the test and got it right
.
Rank the following from smallest current to largest current.
A 1200W microwave connected to 110V outlet.
I=P/U=1200/110=10.9 A
A 1500W water heater connected to 220V outlet.
I=P/U=1500/220=6.8 A
A 100W light bulb connected to 110V outlet.
I=P/U=100/110=0.9 A
A 2000W oven connected to a 220V outlet.
I=P/U=2000/220=9.1 A
A 40W Light bulb connected to a 12V battery.
I=P/U=40/12=3.3 A
Explanation:
The power of an electrical appliance is given by :
[tex]P=V\times I[/tex]
Where
V is the voltage source
I is the current flowing in the circuit
1. For 1200 W microwave, Current, I = 10.9 A
2. For 1500 W water heater, Current, I = 6.8 A
3. For 100 W light bulb, Current, I = 0.9 A
4. For 2000 W oven, Current, I = 9.1 A
5. For 40 W light bulb, Current, I = 3.3 A
Out of the above five appliances, the largest current is flowing in microwave and the smallest current is flowing in the light bulb.
So, the sequence from smallest current to the largest current is :
100 W light bulb ( 0.9 A) < 40 W light bulb (3.3 A) < 1500 W water heater (6.8 A) < 2000 W oven (9.1 A) < 1200 W microwave (10.9 A)
give an example of a situation in which you would describe an object's position in
After walking across a carpeted floor in socks, Jim brings his finger near a metal doorknob and receives a shock. what does that demonstrate
Electric forces can act at a distance
You exert a horizontal force on a heavy piano that rests on a carpeted floor. the piano doesn't budge. if the force you exert on the piano is the "action", what force is its reaction?
Answer:
it will cruch you so the piano exerts on you
Explanation:
Sally and Maria were running around the track during PE. They were not happy and decided to stop and rest once they got to the bleachers. After a 10 minute rest, they started running again, but Sally tripped and fell. At what time during their run did Sally fall for a minute? A) at 4 minutes B) at 14 minutes C) at 15 minutes D) at 20 minutes
Answer:
The answer is A.) 4 minutes
Explanation:
If you look at the graph they started at 15 and when they took a rest it was at 4 mins.
Answer:
B)15 Minutes
The line becomes straight for one min at the fifteen min marker.
Hope this helps
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what type of simple machine is a catapult?( incline plane , lever , pulley , screw , wedge, or a wheel and axle) How do you know ?
Answer: Lever
Explanation:
A catapult as a machine is a lever (1st class) because the fulcrum is between the Effort applied and the load(object) to be launched. A first class lever machine is a machine that has the fulcrum in between the effort and the load which makes a catapult a first class lever.
The handle of the catapult is where the effort is applied, the fulcrum is the point of contact between the rubber tied to the stick and the stick itself and the load is the object to be launched.
A catapult is a type of lever because it uses a rigid arm that pivots around a fixed point to launch a projectile.
A simple machine known as a lever is made up of a rigid bar or board that pivots around a fixed point, also known as a fulcrum. The fulcrum of a catapult is the location where the weapon's arm is joined to the base.
Potential energy is stored in the system when the catapult's arm is retracted. Potential energy is transformed into kinetic energy when the arm is released, which causes the arm to swing forward and fire the projectile.
Seesaws, scissors, and crowbars are a few examples of machines that utilize the lever concept. The lever enables the application of a little force over a longer distance to produce a bigger force over a shorter distance.
Therefore, a catapult is a type of lever. The correct answer is lever. An example of a lever is a catapult.
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When sodium reacts with chlorine, sodium chloride is produced. Andrew represented this reaction with this equation:
Na + Cl2 → 2NaCl
The equation is (BLANK 1) because the number of (BLANK 2) atoms is (BLANK 3) on both sides of the arrow.
BLANK 1
A) Balanced
B) Not Balanced
BLANK 2
A) Chlorine
B) Sodium
BLANK 3
A) Equal
B) Not Equal
A car slows down from 27.7 m/s to 10.9 m/s in 2.37s. What is the acceleration?
A car slows down from 27.7 m/s to 10.9 m/s in 2.37s.Then the acceleration is -7.09 m/sec².
What is acceleration ?Acceleration is the rate at which an object's velocity with respect to time changes. They are vector quantities, accelerations. The direction of the net force acting on an object determines the direction of its acceleration.
An object has positive acceleration if it is accelerating and travelling in the right direction. Positive acceleration was demonstrated in the first example by the speeding car. The acceleration is occurring in the same direction as the car's motion, which is forward and speeding up.
The equation a = v/t denotes acceleration (a), which is the change in velocity (v) over the change in time (t).
The final velocity 'v' =10.9 m/s
The time 't' = 2.37 secs.
Then acceleration = -7.09 m/sec² or, decceleration is 7.09 m/sec².
Thus, the acceleration is -7.09 m/sec².
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What does the Energy Independence and Security Act of 2007 mandate? A. more use of fossil fuels
B. more use of heavy cars
C. more fuel efficient cars
Answer: C
The Energy Independence and Security Act of 2007 mandates the use of more fuel efficient cars where car manufacturers are required to boost fleet wide gas mileage to 35 mp (14.8 km/l) by 2020 in order to help reduce petroleum consumption. It encourages the increase in fuel economy standards for passenger cars. Thus, promote production of fuel-efficient vehicles. Additionally, the act also support the use of electric transportation technology.
The answer is C. more fuel efficient car.s
Sugar mixed in water is an example of a _______________ .
A colloid
B suspension
C pure substance
D solution
E heterogeneous mixture
Answer:
option D is correct. It is a solution.
Explanation:
A physical change occurs when sugar dissolves in water. It is due to the fact that no new substance is formed.the process is reversible.as sugar is solute.water is solvent.What is solute?A solute is a substance that dissolves in a solution. A solvent and one or more solutes make up every solution.
hence, option D is correct. It is a solution.
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How are stone tools or sharp sticks technology
Stone tools and sharp sticks are early technologies that required technical skills and knowledge for their creation and use.
Stone tools and sharp sticks are considered technology due to the technical skills and knowledge required for their creation and usage. The development of stone tools, such as the Oldowan tools, marked a significant advancement in human engineering abilities, enabling tasks like cutting, scraping, and butchering. Furthermore, innovations like hafting, attaching blades to shafts, showcase the early human understanding of materials and design.