Answer: I hope you find it useful
Explanation: Group 2 elements have two valence electrons. The two valence electrons are easily lost in the formation of chemical bonds. Once the two electrons are lost, the atom then has a full outer shell and is therefore more stable.
so, if an atom has valency 2 , then it means that the atom can combine with 2 other atoms .
A force of 10 N is making an angle of 30° with the horizontal. Its horizontal component will be:
A. 4N
B. 5N
C. 7N
D. 8.7 N
Answer:The answer is A
Explanation:just did it on a test
A car generator turns at 400 rpm (revolutions per minute) when the engine is idling. It has a rectangular coil with 300 turns of dimensions 5.00 cm by 6.46 cm that rotates in an adjustable magnetic field. What is the field strength needed to produce a 24.0 V peak emf
Answer:
The field strength needed to produce a 24.0 V peak emf is 0.5913 T
Explanation:
From the formula for maximum emf of a generator,
[tex]emf_{max}= NAB\omega[/tex]
∴ [tex]B = \frac{emf_{max} }{NA\omega}[/tex]
Where N is the number of loops
A is cross section of loops
B is magnetic field strength
ω is the angular frequency of loops
From the question, [tex]emf_{max} = 24.0V[/tex]
N = 300 turns
A = l × b ( since it is a rectangular coil)
A = 6.46 cm × 5.00 cm
A = 0.0646 m × 0.05 m
A = 0.00323 m²
ω = 400 rpm = (400/60)×2π rad/s
ω = 41.8879 rad/s
Putting all the parameters into the formula
[tex]B = \frac{emf_{max} }{NA\omega}[/tex]
[tex]B = \frac{24.0}{300\times0.00323\times41.8879}[/tex]
[tex]B = 0.5913T[/tex]
Hence, the field strength needed to produce a 24.0 V peak emf is 0.5913 T
what are the factors of evaporation and give explanation
Answer:
The three primaryfactors of evaporation are heat, atmospheric pressure (which determines the percentage of moisture) and the movementofair. At the molecular level, there is no strict boundary between the liquid state and the vapor state
Which of the following is a contact force?
A. applied
B. electromagnetic
C. nuclear
D. gravity
applied force is a contact force
if you add km/ hr with another km/ hr what will you get
Answer:
km/hr
Explanation:
Addition and subtraction are commutative
Meaning you can add or subtract in any order because it doesn't change the sum or the difference. So it doesn't change the units.
Answer:
km/ hr + km/ hr =(km+ km)/hr=2km/hr
Explanation:
The first periodic table of elements Mendeleev created contained only 70 elements. True or false?
Explanation:
FALSE
The first periodic table of elements Mendeleev created contained 63 elements.
state and prove Newton's second law of motion
Answer:
HOPE IT HELP YOU A LOT :)
I prove it also .
Answer:
Newtons Second law of motion states that"The rate of change of momentum is directly proportional to the force applied"
A sample of Radon-222 has a half-life of 3.82 days. After 11.46 days, there is 5 grams of Radon-222 remaining. How much Radon-222 was in the original sample?
30 grams
2 grams
15 grams
40 grams
1. Una carga Q1 = + 12 μC se coloca a una distancia r = 0.024 m desde una carga Q2 = + 16 μC. a) Determina la magnitud de la fuerza electrostática que actúa sobre las dos cargas, Q1 y Q2. b) ¿Es la fuerza la atracción o repulsión? 2. Determina la intensidad del campo eléctrico a una distancia radial de r = 48 mm desde una carga de Q = 24 μC. 3. Una carga Q1 = 24 mC se coloca a una distancia r = 0.032 m desde una carga Q2 = - 12 μC. a. Determina la cantidad de energía potencial eléctrica que tiene la carga Q1. b. Determina el potencial eléctrico en la posición de Q2.
Answer:
1. a. 3,000 N
b. Repulsión
2. 46.875 × 10⁶ N/C
3. a. 81,000 J
b. 6.75 × 10⁹ V
Explanation:
1. Los parámetros dados son;
Q₁ = +12 μC, Q₂ = +16 μC
La distancia entre las cargas, r = 0.024
La magnitud de la fuerza electrostática, F, entre cargas se da como sigue;
[tex]F = k \times \dfrac{Q_1 \cdot Q_2}{r^2}[/tex]
Donde, k = constante de Coulomb = 9.0 × 10⁹ N · m² / C²
Por lo tanto, obtenemos;
F = 9.0 × 10⁹ × 12 × 10⁻⁶ × 16 × 10⁻⁶ / 0.024² = 3.000
La magnitud de la fuerza electrostática, entre las cargas, F = 3000 N
(b) Dado que tanto Q₁ como Q₂ son cargas positivas, y las cargas iguales se repelen entre sí, la fuerza es la repulsión.
2) La intensidad de un campo eléctrico, E, se da como sigue;
[tex]E = \dfrac{k \cdot Q}{r^2}[/tex]
La magnitud de la carga, Q = 24 μC
La distancia donde se mide el campo, r = 48 mm = 0.048 m
Por lo tanto, E = 9.0 × 10⁹ × 12 × 10⁻⁶ / 0.048² = 46,875,000 N / C
La intensidad de un campo eléctrico, E = 46,875,000 N / C = 46.875 × 10⁶ N / C
3. La magnitud de las cargas son;
Q₁ = 24 mC
Q₂ = -12 μC
La distancia entre las cargas, r = 0.032 m
un. El potencial eléctrico de una carga, [tex]U_E[/tex] , se da de la siguiente manera;
[tex]U_E = k \times \dfrac{Q_1 \cdot Q_2}{r}[/tex]
Por lo tanto;
[tex]U_E[/tex] = 9.0×10⁹ × 24 × 10⁻³ × (-12) × 10⁻⁶ /0.032 = -81,000
La energía potencial eléctrica entre la carga, Q₁ y Q₂= -81,000 J
b. El potencial eléctrico de Q₁ en Q₂, V₁ = [tex]k \times \dfrac{Q_1 }{r}[/tex]
Por lo tanto, V₁ = 9.0×10⁹ × 24 × 10⁻³/0.032 = 6.75 × 10⁹
El potencial eléctrico de Q₁ en Q₂, V₁ = 6.75 × 10⁹ V
explain why resistors connected in parallel are called current dividers
Explanation:
A parallel circuit is often called a current divider for its ability to proportion—or divide—the total current into fractional parts. Once again, it should be apparent that the current through each resistor is related to its resistance, given that the voltage across all resistors is the same
A and B are 0.200m apart in an electric field. If 800J of work are reuqired to move a 2.00 Columb charge from A to B, what is the electric field stregth?
Answer:
hello
Explanation:
hello dost timi kasto cha
How can a simulation study be used to learn about a planet we have never visited?
In a simulation study you imitate some conditions and characteristics of the real planet. The simulation can be used as a substitute for real data collected on the planet.
Simulation studies can be used for planets we have already visited.
In a simulation study you imitate as many conditions and characteristics as possible of the real thing, in this case the planet you have not visited. By simulating as many conditions as possible you can visualize what the planet might be like and learn things about it without actually visiting it.
Simulation studies cannot be used to learn about a planet we have never visited because we do not know anything about the planet.
A simulation study that is used to learn about a planet by simulating as many conditions as possible, you can visualize what the planet might be like and learn things about it without actually visiting it. The correct option is c.
What is simulation?A simulation is a method of simulating a process or change in the actual world to forecast future events or to explain past events and their causes. These days, simulations are frequently carried out using computers. Scientists use simulations to find answers and to test complicated systems.
A fire drill is used in this instance to get everyone ready for an impending event. In fire drills, the fire alarm is sounded even when there isn't actually a fire.
Therefore, the correct option is c.
To learn more about simulation, refer to the link:
https://brainly.com/question/16359096
#SPJ2
A force of 15N acts on an area of 60m².What is the pressure? *
Answer:
0.25p.a
Explanation:
force=15N area=60m²
so pressure =force/area =15N/60m²=0.25p.a
How does the comets energy change as it moves from point a to point d
Answer:
At point A, the comet has the least kinetic energy because the comet is resting. 3. From point B to point D its orbit's potential energy is decreasing and its kinetic energy is increasing meaning it's moving more and more
Help quick
How does the ramp produce mechanical advantage?
A it reduces the amount of input force needed to do a certain amount of work
B it reduces the distance over which the input force needs to be applied
C it reduces the amount of useful work done on objects move it up the ramp
D what is the overall amount of work done on object moving up the ram
C it reduces the amount of useful work done on objects move it up the ramp
A motorcycle is moving at a constant velocity of 15 meters/second. Then it starts to accelerate and reaches a velocity of 24 meters/second in 3 seconds. What’s the acceleration of the motorcycle over this time? Use .
A.
9 m/s2
B.
8 m/s2
C.
6 m/s2
D.
5 m/s2
E.
3 m/s2
option E
3m/s square
hope it helped u
Lúc 7g bạn an đi từ nhà đến trường với tóc độ trung bình là 20km/h . Bạn đến trường lúc 7g20. Tính khoảng cách từ nhà tới trường?
Answer:
Distance = 6.667 kilometres
Explanation:
Given the following data;
Speed = 20 km/h
Departure time = 7:00
Arrival time = 7:20
Time taken = 20 minutes
To calculate the distance travelled from home to school;
First of all, we would have to convert the value of time in minutes to hours.
Conversion:
60 minutes = 1 hour
20 minutes = X hours
Cross-multiplying, we have;
X = 20/60 = 1/3 hours
Mathematically, the distance travelled by an object is calculated by using the formula;
Distance = speed * time
Distance = 20 * 1/3
Distance = 20/3 =
Distance = 6.667 kilometres
A race car sits on the starting line on a racetrack. when the race starts, the car's tires exert a force on the track. According to newton's third law of motion, what causes the car to accelerate forward?
A. the track surface exerts a force that is larger and in the same direction as the force exerted by th tires.
B. a normal force that is equal in a magnitude to gravity pushes up on the car
C. the force of friction between the car tires and the track pulls the car forward
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Answer:
D. the track exerts a force that is equal and in the opposite direction as the force exerted by the tires
Explanation:
Newton's third law of motion states that for every action, there is an equal and opposite reaction. This speaks of equality in magnitude of force applied but in an opposite direction to one another.
According to this reaction, a car's tires exert a force on the track, this means that in accordance to Newton's third law, the track must exert an equal but opposite force on the car's tires. This causes the car to accelerate forward.
a body of radius R and mass m is rolling horizontally without slipping with speed v. it then rolls us a hill to a maximum height h=3v2/4g
Answer:
mR²/2
Explanation:
Here is the complete question
An object of radius′
R′ and mass ′
M′ is rolling horizontally without slipping with speed ′
V′
. It then rolls up the hill to a maximum height h = 3v²/4g. The moment of inertia of the object is (g= acceleration due to gravity)
Solution
Since it rolls without slipping, there is no friction. So, its initial mechanical energy at the horizontal surface equals its final mechanical energy at the top of the hill.
Since the object is rolling initially, and on horizontal ground, it initial energy is kinetic and made up of rotational and translational kinetic energy.
So, E = K + K'
E = 1/2mv² + 1/2Iω² where m = mass of object, v = speed of object, I = moment of inertia of object and ω = angular speed of object = v/r where v = speed of object and R = radius of object.
Also, the final mechanical energy of the object, E' is its potential energy at the top of the hill. So, E' = mgh.
Since E = E',
1/2mv² + 1/2Iω² = mgh
substituting the values of ω and h into the equation, we have
1/2mv² + 1/2Iω² = mgh
1/2mv² + 1/2I(v/R)²= mg(3v²/4g)
Expanding the brackets, we have
1/2mv² + 1/2Iv²/R²= 3mv²/4
Dividing through by v², we have
1/2m + I/2R²= 3m/4
Subtracting m/2 from both sides, we have
I/2R² = 3m/4 - m/2
Simplifying, we have
I/2R² = m/4
Multiplying through by 2R², we have
I = m/4 × 2R²
I = mR²/2
how do u calculate the kinetic energy of a ball of mass 0.25kg being kicked vertically upwards with a speed of 5m/s
Answer:
3.125J
Explanation:
K.E.= 1/2(mass)(velocity)^2
K.E.=1/2(0.25)(5)^2=3.125
Reference frame definitely changes when also changes
Joule is equal to:
Awatt x metre
B.watt x second
C. Newton x Metre
D. Both b and c
Answer:
The answer is ( D) i. e both b and c.
Choose the option that best suit the question .
An inclined plane of angle Ɵ, acting as a simple machine has a velocity ratio :
(a) sinƟ
(b) 1/sinƟ
(c) cosƟ
(d) 1/cosƟ
(e) sinƟcosƟ
Answer:
(b) 1/sinƟ
Explanation:
A simple machine can be defined as a type of machine with no moving parts but can be used to perform work.
Basically, a simple machine allows for the transformation of energy into work. The six simple machines are; lever, wedge, pulley, screw, wheel and axle, and inclined plane.
Inclined plane is a simple machine set at an angle and then used to lift an object.
In Physics, the velocity ratio of a simple machine is calculated as a ratio of the distance moved by the effort to the vertical distance through which a load is raised.
Mathematically, the velocity ratio of an inclined plane of angle Ɵ, acting as a simple machine is given by the formula;
Velocity ratio (V.R) = 1/sinƟ
Basically, an increase in the angle of inclination (measured in degrees) of an inclined plane increases its velocity ratio.
When should a line graph be used?
A. When the independent variable is continuous and shows a causal link to the dependent variable.
B. When the independent variable is composed of categories and does not show a relationship.
C. When there is no independent variable.
D. When the independent variable is continuous and does not show a relationship to the dependent variable.
Answer:
A. When the independent variable is continuous and shows a causal link to the dependent variable.
Explanation:
A graph can be defined as the graphical representation of data (informations) on horizontal and vertical lines i.e x-axis and y-axis respectively.
In an experiment , the variable being manipulated by an experimenter is known as an independent variable while the dependent variable is the event expected to change when the independent variable is manipulated
Generally, a line graph should be used when the independent variable is continuous and shows a causal link to the dependent variable.
This ultimately implies that, a line graph should be used when the data changes continuously over time and as such there exist a linear relationship between the data (variables).
Highlight 2 factors which shows that heat from the sun does reach the earth surface by convection
Please help!! :)
For this circuit, what will be the voltage drop across R1?
A. 21.3 V
B. 14.2 V
C. 45.0 V
D. 9.47 V
Answer:
Option D. 9.47 V
Explanation:
We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:
Resistor 1 (R₁) = 20 Ω
Resistor 2 (R₂) = 30 Ω
Resistor 3 (R₃) = 45 Ω
Equivalent Resistance (R) =?
R = R₁ + R₂ + R₃ (series connections)
R = 20 + 30 + 45
R = 95 Ω
Next, we shall determine the current in the circuit. This can be obtained as follow:
Voltage (V) = 45 V
Equivalent Resistance (R) = 95 Ω
Current (I) =?
V = IR
45 = I × 95
Divide both side by 95
I = 45 / 95
I = 0.4737 A
Finally, we shall determine, the voltage across R₁. This can be obtained as follow:
NOTE: Since the resistors are in series connection, the same current will pass through them.
Current (I) = 0.4737 A
Resistor 1 (R₁) = 20 Ω
Voltage 1 (V₁) =?
V₁ = IR₁
V₁ = 0.4737 × 20
V₁ = 9.47 V
Therefore, the voltage across R₁ is 9.47 V.
Answer:
9.47
Explanation:
Just Took the Test
By how many times will the kinetic energy of a body increase if its speed is tripled? Show by calculation .
Answer:
9 lần
Explanation:
Answer:
Kinetic energy (k.e) varies directly as v² from the formula
K.E=(mv²/2)
if v=3 then K.e =v²=(3)²=9
A train 90m long stops in a train station with its front buffers in line with a lamp post on the platform. Later it starts off with an average acceleration of 0.45m/s. What will be its speed in kilometers per hour when the tail buffers pass the lamp post P?
Answer:
The speed of the train when the tail buffers pass the lamp post is 9 m/s
Explanation:
The given parameters are;
The length of the train = 90 m
The initial velocity of the train, u = 0
The average acceleration of the train, a = 0.45 m/s²
When the tail buffer pass the lamp post, P, we have;
The distance travelled, s = The length of the train = 90 m
The kinematic equation of motion is given as follows;
v² = u² + 2·a·s
Where;
v = The speed of the train when the tail buffers pass the lamp post
∴ v² = 0² + 2 × 0.45 m/s² × 90 m = 81 m²/s²
Therefore;
v = √(81 m²/s²) = 9 m/s
The speed of the train when the tail buffers pass the lamp post, v = 9 m/s.
Tres personas, A, B, C, jalan una caja con ayuda de cuerdas cuya masa es despreciable. Si la persona A aplica −3 en dirección horizontal y la persona B aplica a su vez 5 en dirección horizontal, ¿Cuál es el valor de la fuerza que debe ejercer la persona C, para que la caja esté en equilibrio físico?
Answer:
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
Explanation:
Si la caja debe hallarse en equilibrio físico, entonces se debe satisfacer la siguiente ecuación:
[tex]F_{A} + F_{B} + F_{C} = 0[/tex] (1)
Si sabemos que [tex]F_{A} = -3[/tex] y [tex]F_{B} = 5[/tex], entonces el valor de la fuerza que debe ejercer la persona C debe ser:
[tex]F_{C} = -F_{A}-F_{B}[/tex]
[tex]F_{C} = -(-3)-5[/tex]
[tex]F_{C} = -2[/tex]
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
joule is a unit of_____and_____
Answer:
Energy and work
.........
Answer:
Work EnergyExplanation:
Joule is a unit of Work and energy .Hope my answer is helpful to you ✌️❣️☪️❇️☪️❣️✌️
