Answer:
The correct option is D
Explanation:
Generally, thermal and electrical conductivity is affected by valence electrons in an atom. These valence electrons carry electric charges (or conduct heat as the case may be) throughout the atom. The fewer the valence electrons, the higher its conductivity - this is as a result of free movement within the atom. The higher the valence electrons, the lesser its conductivity and when the outermost electrons have completely filled the outermost shell, the atom would be an insulator as there won't be carriers of electric charges.
Hence, from the above, sodium would be expected to have the highest electrical and thermal conductivity because it has just one electron in it's outermost shell
Answer:D
Explanation: got it right
Please helpers! I wrote the first questions answer but from there i didnt know how to calculate.
Answer:
3.
Force(f) =2000N
Distance (d) =10m
Time(t)=50 sec
We know,
P=W/t
=f×d/t
=2000×10/50
=400 watt
4.
Force(f) =30N
Distance (d) =10 m
Time(t) =5 sec
We know,
P=w/t
=f×d/t
=30×10/5
=60 watt
The harmfulness of a germ is called?
what is energy?
a. the number of atoms in an object
b. a form of sound
c. the ability to do work
d. the size of an object
(ik its not b or d, but i dont know)
Answer:
c
Explanation:
c. the ability to do work or to produce heat
I need a bit of help on this one, can anyone answer?
Potential energy = m · g · h
-- When you held the ball at 2.0 meters above the floor, it had
(0.5 kg) · (9.8 m/s²) · (2.0 m) = 9.8 Joules of potential energy.
-- After it bounced and went back up as high as it could, it was only 1.8 meters above the floor. Its potential energy was
(0.5 kg) · (9.8 m/s²) · (1.8 m) = 8.82 Joules
-- Between the drop and the top of the bounce, it lost
(9.8 - 8.82) = 0.98 Joule .
-- The energy was lost when the ball hit the floor. During the hit, 0.98 joule of kinetic energy turned to thermal energy, which slightly heated the ball and the floor.
A heavy box is pulled across a wooden floor with a rope. The rope forms an angle of
60 degrees with the floor. A tension of 80 N is maintained on the rope. What actually is
pulling the box across the floor?
Answer:
69.28N
Explanation:
horizontal force
Cos 60°= F(horizontal)/80N
If we cross multiply, we have
F(horizontal)= 80 cos 60°
= 40N
vertical forces
Sin 60°= F(vertical)/80N
If we cross multiply we have
F( vertical) = 80 sin 60°
= 69.28N
Therefore, the vertical force is 69.28N
After a wave passes through a medium, particles in the medium
Answer:
If a particle is affected by a wave, then the particles are displaced. They move along the direction of the wave. Hence, After a wave passes through a medium, particles in the medium are moved along with the wave.
Explanation:
hope this helps you
Sabiendo que el indice de refracción dela gua es 1,33 calcula el ángulo de refracción resultante para un rayo de luz que incide sobre una piscina con un ángulo de incidencia de 50º
Answer:
35.16 degrees
Explanation:
Knowing that the index of refraction of the guide is 1.33, calculate the resulting angle of refraction for a ray of light that falls on a pool with an angle of incidence of 50º
Refractive index, n = 1.33
The angle of incidence, i = 50°
We need to find the angle of refraction. let it is r. It can be calculated using Snells law as follows:
[tex]n=\dfrac{\sin i}{\sin r}\\\\\sin r=\dfrac{\sin i}{n}\\\\r=\sin^{-1}(\dfrac{\sin i}{n})\\\\r=\sin^{-1}(\dfrac{\sin 50}{1.33})\\\\r=35.16^{\circ}[/tex]
So, the angle of refraction is 35.16 degrees.
A model rocket Was built last weekend. We launched it in a nearby field. The rocket took off Straight up with an initial velocity 62.3 m/s. If it accelerates upward at 4.30 m/s2 until the engines stop 3.73 s later: (a) What is the maximum height the rocket reaches? (b) How long is the rocket in the air? (c) What is the velocity of the rocket as it hits the ground?
Answer:
a) y_total = 575.4 m , b) t_total = 22.56 s , c) v = 106.20 m
Explanation:
a) We can solve this exercise using the scientific relations
Let's find the height reached while the engines are running
v₁ = v₀ + a t
v₁ = 62.3 + 4.30 3.73
v₁ = 78.339 m / s
in this time it rose
y₁ = v₀ t₁ + ½ a t₁²
y₁ = 62.3 3.73 + ½ 4.30 3.73²
y₁ = 262.29 m
At this moment the engines are turned off and the rocket continues in a vertical launch, suppose that the acceleration of gravity is constant in this path
v₂ = v₁ 2 - 2 g y₂
at maximum height the velocity is zero (v₂ = 0)
y₂ = v₁ 2 / 2g
y₂ = 78.339 2/2 9.8
y₂ = 313.11 m
the total height is
y_total = y₁ + y₂
y_total = 262.29 + 313.11
y_total = 575.4 m
b) the time the rocket is in the air is
t_total = t₁ + t₂
where t₂ is the time after the engines have shut down
y = y₁ + v₁ t₂ - ½ g t₂²
y = 0
0 = 262.29 + 78.339 t₂ - ½ 9.8 t₂²
t₂² - 15.99 t₂ - 53.53 = 0
t₂ = [15.99 ±√ (15.99² +4 53.53)] / 2
t₂ = [15.99 ± 21.67] / 2
t₂´ = 18.83 s
t₂´´ = -2.84 s
since the time must be a positive quantity the correct result is t2 = 18.83 s, the total time in the air is
t_total = 3.73 + 18.83
t_total = 22.56 s
c) the speed when it hits the ground
We can perform this calculation starting with the maximum height y = 575.4 m where it has zero initial velocity (vo = 0)
v² = v₀² + 2 g y
v = √ 2gy
v = √ (2 9.8 575.4)
v = 106.20 m
5. You require a high-current battery to start a large tractor. While shopping
for this battery, should you be more concerned with the battery's rating
of volts or amps? Explain.
Answer:
I have no clue sorry I wish I could help
A cheetah and a gazelle are grazing in the savannah. The gazelle is 275 meters away from the gazelle safe zone and the cheetah is 455 meters away. If the gazelle can run at 25 m/s and the cheetah can run at 65 m/s will the gazelle get to safety? If not how fast does the gazelle need to run to beat the cheetah by 2 seconds? I
Answer:
1) Yes, the gazelle gets to safety
2) The speed with which the gazelle needs to run, to beat the cheater by 2 seconds is approximately 29.79 m/s
Explanation:
1) The distance of the gazelle, from the gazelle safe zone = 275 m
The distance of the cheetah from the gazelle = 455 m
The speed of the gazelle = 25 m/s
The speed of the cheetah = 65 m/s
Therefore, we have;
Let the time the gazelle reaches the safe zone = t, which gives;
t = 275 m/(25 m/s) = 11
t = 11 seconds
Let the time the cheetah reaches the gazelle = t₁, we have;
455 + 25 × t₁ = 65 × t₁
t₁ = 455/40 = 11.375
t₁ = 11.375 seconds
The gazelle reaches the gazelle safe zone before the cheetah reaches the gazelle
Therefore, the gazelle gets to safety
2) In order for the gazelle to beat the gazelle by 2 seconds, we have;
The time for the cheetah to reach the safe zone = (275 + 455)/65 = 11.23 seconds
Therefore, we have;
In order for the gazelle to beat the gazelle by 2 seconds the time the cheetah reaches the safe zone = 11.23 - 2 = 9.23 s
The speed of the gazelle is then 275/9.23 ≈ 29.79 m/s
Answer: d = r · t d + 300cheertah = 18t gazelle = 16t the running times are equal! (d + 300) / 18 = d / 16 Solve ford then determine time.
sorry if its confusing
If an earthquake wave travels a distance of 4000m in 8 seconds, how fast is the earthquake wave traveling?
4000 ÷ 8 = 500
Its 500 m/s as shown in the calculation above.
A bungee cord stretches 17 meters and has a spring constant of 130 N/m. How much energy is stored
in the bungee?
Answer:
U = 18,785 J
Explanation:
Elastic Energy
Elastic energy is energy stored in an object due to a force that temporarily changes its shape, such as shrinking or stretching.
The elastic energy can be calculated as follows:
[tex]\displaystyle U=\frac{1}{2}k(\Delta x)^2[/tex]
Where k is the spring constant, and \Delta x is the change in the size of the spring.
The bungee cord stretches \Delta x =17 m, and k=130 N/m, thus:
[tex]\displaystyle U=\frac{1}{2}130(17)^2[/tex]
U = 18,785 J
Which statement best describes the two reactions?
A Upper C l subscript 2 plus upper H subscript 2 right arrow 2 upper H upper C l.
B Superscript 2 subscript 1 upper H plus superscript 3 subscript 1 upper H right superscript 4 subscript 2 upper H e plus superscript 1 subscript 0 n.
Reaction A involves a greater change, and reaction B involves a change in element identity.
Reaction B involves a greater change and a change in element identity.
Reaction A involves a greater change and a change in element identity.
Reaction B involves a greater change, and reaction A involves a change in element identity.
Answer:
b
Explanation:
i guessed annd got it right
Answer:
Reaction B involves a greater change and a change in element identity.
Explanation:
What is the average speed of the Earth after one orbit if it travels 585.6 million miles in 12 months?
Answer:
Forty-eight million eight hundred thousand
Explanation:
You divide 585.6/12. I really hope this helps!!
A 5.00 kg firecracker explodes into two parts: one part has a
mass of 3.00 kg and moves at a velocity of 25.0 m/s towards
the west. The other part has a mass of 2.00 kg. What is the
velocity of the second piece as a result of the explosion?
a -28.7 m/s
b 15.8 m/s
C-37.5 m/s
d 43.2 m/s
Answer:-37.5 m/s
Explanation:
Answer:
-37.5
Explanation:
1. Isotopes have a different nubmer of neutrons in the nucleus. These atoms would have different
as a result. *
A) identities
B) charges
C) atomic numbers
D) atomic masses
Answer:
i believe atomic mass
Explanation:
If an element forms a 3+ ion in which group of the periodic table would you expect to find it?
A. 15
B. 5
C. 13
D. 2
If an element forms a 3+ ion, one can expect to find it in group 13 of the periodic table (option C).
What is the periodic table?Periodic table is a tabular chart of the chemical elements according to their atomic numbers so that elements with similar properties are in the same group (column).
The periodic table is made up of vertical columns called group and horizontal rows called periods.
Elements in group 13 form ions with +3 and +1 charges. The elements are as follows:
boron (B)aluminum (Al)gallium (Ga)indium (In)thallium (Tl)nihonium (Nh)Therefore, group 13 elements in the periodic table form +³ ions.
Learn more about periodic table at: https://brainly.com/question/11155928
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Which part of the eye is responsible for the color of the eye?
OA.
cornea
O B.
iris
O c.
lens
OD.
retina
Answer:
D
Explanation:
As the frequency of a wave decreases, the wave's -
Answer:
When frequency increases more wave crests pass a fixed point each second. That means the wavelength shortens. So, as frequency increases, wavelength decreases. The opposite is also true—as frequency decreases, wavelength increases.
i need help solving this,
Answer:
8n
Explanation:
1. how Orienteering is an ideal sport for the most promotion of
physical activity and lifetime sports.
Answer:
Because it comprises both physical and mental activities.
Explanation:
Orienteering is a sport that is known for its physical and mental activities. It is an ideal sport for the most promotion of physical activity and lifetime sports because it involves moving through the wild or difficult terrain. This takes energy to be competitive, and it also requires participants to take challenging decisions now and then.
People of different ages can participate and allows them to apply real-world decision-making skills to the competition. It also gives participants the chance to learn about themselves more and how to face different situations.
What is the first step when adding two vectors that are not perpendicular?
Answer:
Two non-perpendicular vectors will not form a right triangle. Yet it is possible to force two (or more) non-perpendicular vectors to be transformed into other vectors that do form a right triangle. The trick involves the concept of a vector component and the process of vector resolution.
a person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. Use the vertical motion model, h = -16t squared + vt + s, where v is the initial velocity in feet per second and s is the height in feet, to calculate the amount of time the baseball is in the air before it hits the ground. Round your answer to the nearest tenth if necessary.
Time in air:_____ seconds
Answer:33s
Explanation:
Answer: 3.3 seconds
Explanation:
I just did it
Cuanta fuerza se necesita lara evitar que una piedra de 20N caiga?
Answer:
Reaction is 20N.
Explanation:
In general, Newton's third law of motion explains that when a force is applied on an object, a reaction of equal magnitude applies in the reverse direction of the force.
i.e F = -R
This implies that, reaction is a force in the opposite direction to that of the force applied.
Force can also be related to the weight of an object as;
F = W = mg
Thus to prevent the 20N stone from falling, a force of 20N is applied in the opposite direction. So the reaction, R is 20N.
A student creates a circuit using a 10V battery, as shown in the picture below.
38
Battery
Switch
20
What is the current in the circuit?
Answer:
I = 2 [amp]
Explanation:
To solve this problem we must use ohm's law, which tells us that the voltage is equal to the product of the current by the resistance.
The resistances in the diagram are connected in series, in this way the total resistance will be equal to the algebraic sum of the resistivity.
R = R1 + R2
R = 3 + 2
R = 5 [ohm]
Now, using ohm's law we have:
V = I*R
where:
V = voltage = 10 [V]
I = current [amp]
R = resistance = 5 [ohm]
I = V/R
I = 10/5
I = 2 [amp]
help please, will give brainlist!
Why does it feel cooler at 90°F when the relative humidity is 30% compared to the same temperature and the relative humidity is 80%?
a. Because the drier air evaporates moisture off your skin more easily.
b. There is no real difference because the temperature is the same.
c. Because there is less air movement at 80% humidity.
d. Because the lower humidity brings down the temperature.
What physical property causes liquids to not separate in a container?
A) density
B) boiling point
C) specific heat
Answer:
B) boiling point
Explanation:
The movement of the particles causes the shape of the liquid to change. The liquid will flow and fill to the lowest part of the container, in the shape of the container
But the volume does not change. The limited amount of space between the particles means that the liquid has only very limited compressibility.
Answer:
A) Density
Explanation:
If a 53 kg Boulder falls off a cliff, what is the force with which it will hit the ground?
Answer: 519.4 N
Explanation:
53 kg x 9.8 m/s = 519.4 N
If a 53 kg Boulder falls off a cliff, the force with which it will hit the ground is 519.4 N.
What is force?A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.
Given in the question a 53 kg Boulder falls off a cliff, what is the force with which it will hit the ground,
force = mass * acceleration due to gravity
= 53 kg x 9.8 m/s
= 519.4 N
If a 53 kg Boulder falls off a cliff, the force with which it will hit the ground is 519.4 N.
To learn more about force refer to the link:
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Rolling Balls LAB - ANSWER SHEET (45 pts)
QUESTIONS:
1. What is the formula for calculating speed? (1 pt)
2. If you were trying to determine if cars in your neighborhood were traveling at or below the posted speed limit, how would you do it? (2 pts)
3. Create a hypothesis as an if-then statement. (2 pts)
4-15. Fill in the Data Table for Balls #1 and #2 (2 pts per blank)
Ball #1 (Describe the ball) - ____________________________________________________
Trial Time to travel 2 meters (seconds)
1
2
3
Average Time
Using the formula s = d/t, calculate the average speed of Ball #1: _____________________
Ball #2 (Describe the ball) - ____________________________________________________
Trial Time to travel 2 meters (seconds)
1
2
3
Average Time
Using the formula s = d/t, calculate the average speed of Ball #2: _____________________
16. Based on your data, which ball was the fastest? (1 pt)
17. Why do you think it was the fastest? (2 pts)
18. Was your hypothesis correct? (1 pt)
19. Do you think size of the ball had anything to do with the speed of the ball? (2 pts)
20. Why or why not? (2 pts)
21. Name 2 factors that could determine the speed at which a ball rolls. (2 pts)
22. A car travels 3 kilometers and it takes 2 minutes to cover that distance What is the speed of the car? (2 pts)
23. A train is traveling at 60 km/hr. It travels for 2 hours. How far will it travel? (2 pts)
24. A girl is riding her bicycle at 10 miles/hour. At the end of the ride she has traveled 35 miles. How long did it take her to cover that distance? (2 pts)
Answer:
1. s = d/t
22. d = 3km = 3000m
t = 2m = 60s
s = 3000/60
= 300/6
= 50m/s
Therefore, the speed of the car is 50 m/s.
23. s = 60km/hr
t = 2hrs
d = s × t
d = 60 × 2
d = 120km
The car travels for 120km.
24. s = 10mile/hr
d = 35km
t = d/s
t = 35/10
t = 3.5hrs
The girl takes 3.5 hours to cover the distance
On the same spring day, a station near the equator has a surface temperature of 25°C, 15°C higher than the middle-latitude city mentioned in part a. Vertical soundings reveal an environmental lapse rate of 6.5°C per kilometer and indicate that the tropopause is encountered at 16 km. What is the air temperature at the tropopause?
Answer:
The air temperature at the tropopause is - 79 °C
Explanation:
We know that a station near the equator has a surface temperature of 25°C
Vertical soundings reveal an environmental lapse rate of 6.5 °C per kilometer.
The tropopause is encountered at 16 km.
In order to find the air temperature at the tropopause we are going to deduce a linear function for the temperature at the tropopause.
This linear function will have the following structure :
[tex]f(x)=ax+b[/tex]
Where ''[tex]a[/tex]'' and ''[tex]b[/tex]'' are real numbers.
Let's write [tex]T(x)[/tex] to denote the temperature '' T '' in function of the distance
'' x '' ⇒
[tex]T(x)=ax+b[/tex]
We can reorder the function as :
[tex]T(x)=b+ax[/tex] (I)
Now, at the surface the value of ''[tex]x[/tex]'' is 0 km and the temperature is 25°C so in the function (I) we write :
[tex]T(0)=25=b+a(0)[/tex] ⇒ [tex]b=25[/tex] ⇒
[tex]T(x)=25+ax[/tex] (II)
In (II) the value of ''[tex]a[/tex]'' represents the change in temperature per kilometer.
Because the temperature decrease with the height this number will be negative and also a data from the question ⇒
[tex]T(x)=25-(6.5)x[/tex] (III)
In (III) we deduced the linear equation. The last step is to replace by [tex]x=16[/tex] in (III) ⇒
[tex]T(16)=25-(6.5)(16)=-79[/tex]
The air temperature at the tropopause is - 79 °C