Answer:
Oxygen-Symbol-O Potassium Symbol-K
A) Valency is the combining capacity of any element. Valence electrons refers to the electrons found in the outermost shell of the atom of the element.
B) Symbol and valency:
Oxygen(O) = (At. no. 8) = -2(Valency)Potassium(K) = (At. no. = 19) = +1(Valency)C) The reaction would be:
[tex] \large{ \boxed{ \rm{2Mg + O_2 \longrightarrow \: 2MgO}}}[/tex]
Reactants = Magnesium and Oxygen Products = Magnesium oxideWord equation:[tex] \large{ \boxed{ \rm{Magnesium + Oxygen \longrightarrow Magnesium oxide.
}}}[/tex]
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A 1.00-kg glider attached to a spring with a force constant 25.0 N/m oscillates on a frictionless, horizontal air track. At t = 0, the glider is released from rest at x = -2.80 cm (that is, the spring is compressed by 2.80 cm). (a) Find the period of the glider's motion. How does the period depend on the mass and the spring constant? Does it depend on the amplitude of oscillation? s (b) Find the maximum values of its speed and acceleration. speed m/s acceleration m/s2 (c) Find the position, velocity, and acceleration as functions of time. (Where position is in m, velocity is in m/s, acceleration is in m/s2, and t is in s. Use the following as necessary: t.) x(t) = v(t) = a(t) =
Answer:
a) T = 1.26 s , b) v_max = 0.14 m / s , a_max = 0.7 m / s²
c) x = 0.028 cos (5 t) , v = - 0.14 sin 5t, a = - 0.7 cos 5t
Explanation:
This is a simple harmonic motion exercise that is described by the equation
x = A cos (wt +Ф)
with
w = √ (k / m)
let's apply this expression to our case
a) Angular velocity is related to frequency
w = 2π f
frequency and period are related
f = 1 / T
we substitute
2π / T = √ (k / m)
T = 2π √(m / k)
let's calculate
T = 2π √(1/25)
T = 1.26 s
In the expression for the period, the amplitude does not appear, therefore there is no dependence, as long as Hooke's law is fulfilled, which is correct for small amplitudes.
b) in the initial equation we have the position as a function of time, let's use the definition of speed and acceleration
v = dx / dt
v = - A w sin (wt + Ф)
the speed is maximum when the sine is -1
v_max = A w
w = √ (k / m)
w = √ 25/1
w = 5 rad / s
the amplitude of the movement is equal to the maximum compression of the spring
A = 2.8 cm = 0.028 m
we substitute
v_max = 0.028 5
v_max = 0.14 m / s
acceleration
a = dv / dt
a = - A w² cos (wt + Ф)
the acceleration is maximum when the cosine is -1
a_max = A w²
let's calculate
a_max = 0.028 5²
a_max = 0.7 m / s²
c) let's start by finding the phase constant
v = -A w cos (wt + Ф)
at t = 0 they indicate that the system has v = 0
0 = -A w sin (0 + Ф)
Ф = sin⁻¹ 0
Ф = 0
we write the equation
x = 0.028 cos (5 t)
v = - A w sin (wt + Ф)
v = - 0.028 5 sin (5t + 0)
v = - 0.14 sin 5t
acceleration
a = - A w² cos (wt + Ф)
a = - 0.028 5 2 cos (5 t + 0)
a = - 0.7 cos 5t
i)Distinguish between different methods of charging. ii) You are provided with a positively charged gold leaf electroscope. State and explain what happens when a. a glass rod rubbed with silk is brought near the disc of electroscope. b. an ebonite rod rubbed with fur is brought near the disc of electroscope. c. an uncharged metal rod is brought near the disc of electroscope d. a glass rod rubbed with silk is rolled on the disc of electroscope.
Answer:
Explanation:
On rubbing a glass rod with silk, the electrons from the glass rod get transferred to the silk. The silk now has an excess of electrons and so is negatively-charged. On the other hand, the glass rod is deficient in electrons and hence is positively-charged.
In the above case, the silk undergoes negative electrification.
Now, when the positively charged glass rod is touched on the disc of a negatively charged gold leaf electroscope, the electrons shifts towards rod, hence amount of charge on gold leaves decreases and the divergence between the gold leaves decreases as unlike charges attract each other.
Hence, the divergence decreases when a glass rod rubbed with silk is brought near the disc of negatively charged electroscope.
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An aircraft travelling at 600km/h accelerates steadily at 10km/h per second. Taking the speed of sound as 1100km/h at the aircraft's altitude how long will it take to reach the sound barrier?
speed of sound is the final velocity [tex] v=1100[/tex]
and initial velocity $u=600$ , $a=10$
$v=u+at$
$t=\dfrac{v-u}{a}= \dfrac{500}{10}$
$\implies t=50 h$
What is a potential psychological outcome of regulary playing sports
This question is incomplete because the options are missing; I found the complete question:
What is a potential psychological outcome of regularly playing sports? Select one of the options below as your answer:
a. restlessness
b. improved mood
c. depression
d. lack of energy
The answer to this question is B. Improved mood
Explanation:
Practicing a sport regularly has multiple positive effects including physical and psychological benefits. In the case of psychological effects, this includes an improved mood, this is because practicing a sport reduces stress significantly and it is often associated with positive emotions such as motivation, confidence, or pride. Moreover, interacting with others in group sports allow individuals to positively interact with others, which contributes to a better mood. Thus, one potential psychological outcome of playing sports is an improved mood.
If a suitcase has a mass of 20 kg, what is the force of gravity acting on it?
Explanation:
Assuming the suitcase is near the surface of the earth, g = 9.8 m/s².
F = ma
F = (20 kg) (9.8 m/s²)
F = 196 N
Hi :) how to do this?
Answer:
The answer is b
Hope this helps you!
What is the goal of the scientific method
Answer:
Regardless of how the steps are documented, the goal of scientific method is to gather data that will validate or invalidate a cause and effect relationship.
Hope this helped!!!
Eli and Andy want to find out which of the two is stronger. Eli pushes a table with a force of 120 newtons while Andy pushes the table from the opposite side with a force of 125 newtons. Ignoring the masses of Eli and Andy, what is the resultant acceleration of the table if its mass is 10.0 kilograms?
Answer:
a = 0.5 m/s²
Explanation:
the type of problem is called a Newtons second law of motion.
and the equation would be the sum of F = m * a where m = mass and a = acceleration
forces are 125N and the opposite direction is 120N
Eli pushes the table with a force of 120N towards Andy
and
Andy pushes the table with a force of 125N towards Eli
mass of table given as 10 kg.
using the equation
120N - 125N = 10kg * a
a = (120-125) / 10
a = -0.5 m/s² so the acceleration is in the direction of Andy's force towards Eli.
therefore a = 0.5 m/s²
Answer:
B.
0.50 meters/second2
Explanation:
When using science to investigate physical phenomena, which characteristic of the event must exist?
predictable
measurable
provable
readable
READ NEXT SECTION
ASK FOR HELP
The correct answer is B. Measurable
Explanation:
The use of science to investigate a phenomenon implies using measurements and observations to better understand a phenomenon or test a hypothesis. Moreover, science focuses on natural phenomena that can be objectively studied through measurement instruments such as a thermometer, balance, hydrometer, etc.
In this context, for a phenomenon to be studied by science this needs to be measurable because the use of precise instruments as wells as numbers allow scientist to analyze and understand a phenomenon. Moreover, phenomena that depend on personal perspectives and cannot be measure is considered as non-scientific.
What is the Opportunity Cost in textbooks from going from point A to B?
Answer:
60.00
Explanation:
you welcome
*If someone says v-u=0 ,what does it mean. *What is the relation among mometum,mass and velocity. *A moving bus a little distance forward even when breaks are applied on it which Newton's laws work here? *Under what conditions acceleration of a moving object will be zero?
Answer:
1) It means that the acceleration is 0
2) Momentum, p = Mass, m × Velocity, v
3) Newton's second law of motion
4) The conditions where there are no resultant forces acting on the object
Explanation:
1) The value v - u = 0 means that the acceleration is 0
The relation between v and u is v = u + a·t
v - u = a·t
When v - u = 0 we have;
a·t = 0
a = 0 or t = 0
Acceleration, a = 0
2) The relation between momentum, mass and velocity is
Momentum, p = Mass, m × Velocity, v
p = m × v
3) The bus moving a little distance forward even when the breaks are applied is due to the following relation;
Force = Rate of change of momentum produced
Which is Newton's second law of motion
Therefore, where the the force is low, the rate of change of the momentum and therefore, the velocity will be low, and the bus will still move further after applying the breaks
4) According to Newton's first law of motion, the conditions under which the acceleration of a moving object will be zero includes conditions where there are no resultant forces acting on the object.
a metre rod on wedge is example of unstable equilibrium.why
Answer:
because it has no balance
An inventive child wants to reach an apple in a tree without climbing the tree. Sitting in a chair connected to a rope that passes over a frictionless pulley, the child pulls on the loose end of the rope with such a force that the spring scale reads 250 N. The child’s true weight is 320 N, and the chair weighs 160 N. (a) Show that the acceleration of the system is upward and find its magnitude. (b) Find the force the child exerts on the chair.
Answer:
(a) 0.42 m/s²
(b) 83 N
Explanation:
Assuming g = 10 m/s².
Draw free body diagrams for the child and the chair.
There are three forces on the child:
Tension force T pulling up,
Weight force Mg pulling down,
and normal force N pushing up.
There are three forces on the chair:
Tension force T pulling up,
Weight force mg pulling down,
and normal force N pushing down.
Sum of forces on the child in the y direction:
∑F = ma
T + N − Mg = Ma
Sum of forces on the chair in the y direction:
∑F = ma
T − N − mg = ma
Add the equations together to find the acceleration.
2T − Mg − mg = Ma + ma
a = (2T − Mg − mg) / (M + m)
a = g (2T − Mg − mg) / (Mg + mg)
a = (10 m/s²) (2 × 250 N − 320 N − 160 N) / (320 N + 160 N)
a = 0.42 m/s²
Plug into either equation to find the normal force.
T + N − Mg = Ma
250 N + N − 320 N = (320 N / 10 m/s²) (0.42 m/s²)
N = 83 N
please help ASAP.
these are examination questions ..
no nonsense answers .
i will mark as brainliest if you got it correct .
Answer:
1st question c part
2nd question c part
Is it (P)otential or (K)inetic energy
Answer:
Think of it like this potential energy is exactly what it sounds like it has potential. while kinetic energy which is what the body possesses by virtue of being in motion.
Explanation:
If a car has a speed of 36m/s how long will it take to go 100 m
Match the words to the correct blanks in the sentences. Use each choice only once. a. The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by________. b. As a protostar shrinks in size, its central temperature rises along with its________. c. A star that has not yet finished forming is called a_______. d. A forming star spins more rapidly as it collapses because of conservation of________. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a________.A. thermal pressureB. angular momentumC. energy balanceD. degeneracy pressureE. brown dwarfF. gravitational equilibriumG. protostar
Answer:
The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____
John owns a used 2003 mustang Mach 1, he spots a news crew with a bunch of people what should he do? A) Rev his engine at the highest RPM B) Do a burnout C) Drive near the Crowd and drop a gear and hurl into the crowd D) ALL OF THE ABOVE
Each of the three choices is tasteless, exhibitionist, juvenile, and dangerous. John should do none of them.
Encountering a news crew, there's no reason for John to call attention to himself in a childish way, or interfere with their work in any way.
What he should do is:
==> Slow down
==> Pass the scene cautiously
==> Resume his normal, legal speed quietly, in case the crew happens to be recording audio at the moment.
Mysteriously, this course of action is nowhere to be found among the choices listed.
Answer:
all three options :)
Explanation:
cuz merica
why do objects in equilibrium have a net force of 0?
Answer:
Because there is no net force acting o an object in equilibrium.
Explanation:
When object is in equilibrium (either at rest or moving with constant velocity, the net force acting o it is zero.A vector can only have zero magnitude fall of its components are zero this means that all forces acting on the object are balanced.
What is The distance traveled by a vehicle in 12 minutes,if it’s speed is 35km/h
Answer: 7 km
Explanation: 12 minutes is 1/5 of an hour. 35/5=7
At a camp site there are tents of 2 shades. 1 made with black fabric and the other with white fabric. Which one will you prefer for resting on a hot summer afternoon. Give reason for your choice
Answer:
Explanation:
On a hot summer afternoon the tent made up of white fabric will be preferred because white colour is a bad absorber and good reflector of heat. Hence, it will be more convenient to stay under fabric tent made of white during this season because heat will be reflected which makes shade provided by such tent to be cool and enjoyable.
While the black fabric tent will be preferred during winter because black materials are good absorber of heat and are poor reflector.
7. Calculate the force applied on an object if the Pressure exerted is 90 Pascal over an area of 900 cm2.
Answer:
Explanation: pressure = force / area
Rearrange to get: force = pressure x area. 900 cm2 = 0.09 m2
force = 90 x 0.09
= 8.1 N
famous comparative and superlative form
Answer:
comparative----more famous, superlative----- most famous
[tex]\huge{\fbox{\red{Answer:}}}[/tex]
Word Given :Famous
___________________✍
Comparative Form : more famous
Superlative Form : most famous
Hope you understand❣
A driver of a car stopped at a gas station to fill up his gas tank. He looked at his watch, and the time read exactly 4 : 45 4:45 p.m. At this time, he started pumping gas into the tank. At exactly 4 : 50 4:50, the tank was full and he noticed that he had pumped 12.5 12.5 gallons. What is the average rate of flow of the gasoline into the gas tank
Answer:
Explanation:
Average rate = gallons / minutes
If 12.5gallons in 5mins
Xgallons in 1mins
12.5/5 = 2.5gallons per minute
A type of cuckoo clock keeps time by having a mass bouncing on a spring, usually something cute like a cherub in a chair. What force constant is needed to produce a period of 0.500 s for a 0.0150-kg mass
Answer:
the force constant k = 2.369 N/m
Explanation:
Given that:
A type of cuckoo clock keeps time by having a mass bouncing on a spring, usually something cute like a cherub in a chair.
with period T = 0.500 s and a mass of 0.0150 kg, Then the force constant can be calculated by using the formula:
[tex]\mathtt{T = 2 \pi \ \sqrt{\dfrac{m}{k} }}[/tex]
where;
T = time period
m = mass
k = force constant.
By making k the subject of the formula; we have:
[tex]\mathtt{T^2 = 4 \pi^2 (\dfrac{m}{k})}[/tex]
[tex]\mathtt{k =\dfrac{4 \pi ^2 \ m}{T^2}}[/tex]
replacing our given values , we have:
[tex]\mathtt{k =\dfrac{4 (3.142) ^2 \ \times 0.0150 }{0.5^2}}[/tex]
[tex]\mathtt{k =\dfrac{39.49 \ \times 0.0150 }{0.25}}[/tex]
[tex]\mathtt{k =\dfrac{0.59235 }{0.25}}[/tex]
k = 2.369 N/m
According to the information available in the question, the force constant is 2.37N/m.
Using the relation;
T = 2π√m/k
T = period = 0.500 s
m = mass in kilograms = 0.0150-kg
k = spring constant = ?
Making k the subject of the formula;
k = 4π^2m/T^2
k = 4 × (3.142)^2 × 0.0150/(0.500 )^2
k = 2.37N/m
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Which describes a grizzly bear’s habitat? all the biotic factors in the ecosystem all the abiotic factors in the ecosystem the role of the bear in the ecosystem the physical area where the bear lives
Answer:
I found this question elsewhere on brainly and the answer was verified. Here it is!
Explanation:
Grizzly bear habitats is the habitat or the physical space where the bear lives. Grizzly bears can be found in many different habitats from dense forests to subalpine meadows, arctic tundra and open plains. We can also conclude that all of the bears live in grizzly bear's habitat in order to survive.
The best description of a grizzly bear’s habitat is:
D. the physical area where the bear livesA habitat is the natural surrounding or place where an organism lives, grows and competes with other organisms for resources. It is a physical area.
There are three major types of habitat which includes:
Freshwater habitat: This refers to the area of water where animals live. Examples of animals that live in a freshwater habitat includes: sea turtle, fishes, etc. Examples of freshwater habitat include:RiversLakesPond, etcMarine water habitat: This is where a group of organisms live. Examples include:OceansSeas, etc.Coastal habitat: This is an intersection between the land and sea habitats.A grizzly bear is a subspecies of brown bear and is resident in the northern plains of America and their habitat is a physical location where they live.
Therefore, the correct answer is option D
Read more here:
https://brainly.com/question/19482426
answer answer answer it it it
Answer:
Parachutes
Explanation:
Your parachute allows you to descend more slowly because it lowers terminal velocity by increasing your air resistance. Most parachutes are designed to create a large amount of drag and allow you to land at a safe, low speed.
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Brandon buys a new seadoo he goes 12 km north from the beach he jumps wakes for 6 km to the east the chases a boat 10 km north what distance did he cover what was his displacement
Answer:
Distance covered 28 km
displacement is 22.8 km North-East
Explanation:
Distance shows how far apart objects or points are from each other. The distance he covered is the sum of all the distance travelled. Therefore:
Distance covered = 12 km + 6 km + 10 km = 28 km
Displacement is a vector quantity (has direction). It is the overall change in position.
The total distance traveled north = 12 km + 10 km = 22 km
The distance traveled east = 6 km
The displacement (d) is:
d² = 22² + 6² = 484 + 36
d² = 520
d = √520 = 22.8 km
Therefore the displacement is 22.8 km North-East
Distance covered 28 km
displacement is 22.8 km North-East
The calculation is as follows:
Distance covered
= 12 km + 6 km + 10 km
= 28 km
Now
The total distance traveled north = 12 km + 10 km = 22 km
And,
The distance traveled east = 6 km
So,
The displacement (d) is:
[tex]d^2 = 22^2 + 6^2\\\\ d^2 = 520\\\\d = \sqrt520[/tex]
= 22.8 km
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Using your own word, tell me what is the difference between an element and a compound? Make sure to give an example of each.
Answer:
Hey there!
Elements only contain one type of atom, and a compound contains atoms of different elements chemically combined together. For example, gold is an element, because it only is made of gold atoms, where water or H2O is a compound.
Let me know if this helps :)
Answer:
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. Elements contain only one type of atom.
Example:
Explanation:
Describe the motion of water waves.
Answer:
Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases.
