Answer:
Doppler Theory
Explanation:
it's a theory regarding the change in wave frequency during the relative motion between a wave source and its observer.
28 Why is soft iron used for the core of an electromagnet?
А Soft iron easily becomes a permanent magnet.
B Soft iron is a good electrical conductor.
с Soft iron is a poor thermal conductor.
D Soft iron loses its magnetism when the current in the coil is switched off.
Answer:
An electromagnet is a form of magnet that is made by the passage of electric current through a coil of wire. The core of an electromagnet increases the strength of the produced magnetic field
Soft iron is used as the core of an electromagnet because soft iron is a magnetic material and therefore it is permeable to and becomes magnetized by the magnetic field coming from the flowing current, thereby allowing more flux to pass through the core of the electromagnet, producing a magnetic field strength that is several times that of an air core electromagnet as the relative permeability (to magnetic flux, compared to vacuum) of soft iron is about 64 × 10³
However, once the current is switched, the soft iron does not remain its magnetic, and therefore, the electromagnet becomes demagnetized, thereby being able to maintain its electromagnetic characteristics (being made magnetic by the flow of electric current)
Explanation:
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
The radius of the base of a wooden cylinder 2m and its altitude is 7m. What is its mass?
Answer:
88 m ^2
Explanation:
A person has power of 550 watt. What does it mean?
Answer:
It means that person can do work or can posses energy at a rate of 550 watts.
Or : can posses energy of 550 joules in one second.
Explanation:
[tex]{ \bf{power = \frac{work}{time} }}[/tex]
Question 7 of 25
Which two chemical equations are balanced?
O A. 2PBrg + 3Cl2 - 2PC13 + 3Br2
O B. 2Na+ MgCl2
2NaCl + Mg
-
C. 2LIOH + 2H2S - Li2S + 2H20
D. 2AgNO3 + NaCl - NaNO3 + 2AGCI
Answer:
2PBr₃ + 3Cl₂ → 2PCl₃ + 3Br₂
2Na + MgCl₂ → 2NaCl + Mg
Explanation:
A balanced chemical equation is a chemical equation that have an equal number of elements of each type on both sides of the equation
Among the given chemical reactions, we have;
2PBr₃ + 3Cl₂ → 2PCl₃ + 3Br₂
In the above reaction;
The number of phosphorus, P, on either side of the equation = 2
The number of bromine atoms, Br, on either side of the equation = 6
The number of chlorine atoms, Cl, on either side of the equation = 6
Therefore, the number of elements in the reactant side and products side of the reaction are equal and the reaction is balanced
The second balanced chemical reaction is 2Na + MgCl₂ → 2NaCl + Mg
In the above reaction, there are two sodium atoms, Na, one magnesium atom and two chlorine atoms on both sides of the reaction, therefore, the reaction is balanced
1) The position of an object to the north of a flagpole is given by x(t) = bt2 – c , where b and c are constants.
a) What is v(t), the velocity of the object as a function of time?
b) What is a(t), the acceleration of the object as a function of time?
c) At some time t the object is located at the flagpole. What is the velocity of the
object at that instant?
Answer:
a) The velocity of the object as a function of time, v(t) is 2·b·t
b) The acceleration of the function of time, a(t) is 2·b
c) The time at which the object is at the flagpole is t = √(c/b)
Explanation:
The function that gives the position of the object north of the flagpole, x(t) is presented as follows;
x(t) = b·t² - c (b and c are constants)
a) The velocity of the object as a function of time, v(t), is derived as follows
v(t) = x'(t) = d(b·t² - c)/dt = 2·b·t
The velocity of the object as a function of time, v(t) = 2·b·t
b) The acceleration of the function of time, a(t) = v'(t) = d(2·b·t)/dt = 2·b
c) The time at which the object is at the flagpole is given by the x-intercept of the function, where x(t) = 0, as follows;
At the x-intercept, we have, x(t) = 0 and x(t) = b·t² - c
∴ 0 = b·t² - c, which gives
b·t² = c
t² = c/b
t = ±√(c/b), we reject the negative value to get;
The time at which the object is at the flagpole, t = √(c/b).
a bus starts to move from rest if its velocity becomes 90 km per hour after 8 speed calculate its acceleration.
write with full process.
answer=3.13ms–²
Answer:
Acceleration, a = 3.13 m/s²
Explanation:
Given the following data;
Initial velocity = 0 m/s (since it's starting from rest).
Final velocity = 90 km/h
Time = 8 seconds
Conversion:
90 km/h = (90 * 1000)/3600 = 25 m/s
To find the acceleration, we would use the first equation of motion;
V = U + at
Where;
V is the final velocity.
U is the initial velocity.
a is the acceleration.
t is the time measured in seconds.
Substituting into the equation, we have;
25 = 0 + a*8
25 = 8a
Acceleration, a = 25/8
Acceleration, a = 3.125 ≈ 3.13 m/s²
Make a tree diagram based on the topic motion which includes all the concept like uniform & non uniform motion accelerated motion equation of motion motion etc
I think it is a education tips
Think of a body which is at rest but not in equilibrium
Answer:
I think the sun is the right answer
make a list of principle of lever.
Answer:
The force applied to make the object move
Answer:
input work = output work
E * ED = L* LD
Explanation:
The principle of lever is that input work is always equal to output work .
how does she hold a newspaper while reading without using the lens? why?
Ра:
5. Mass of the earth is 6x10-kg and its radius is 6400km. What is the
mass of a man weighting 977N?
(99.99kg)
ma
Orth
be
Answer:
what do u need help with
Explanation:
Pа: 5. Mass of the earth is 6x10-kg and its radius is 6400km. What is the mass of a man weighting 977N? (99.99kg) ma. Orth be.
Use the KMT to explain what happens to water vapor when it encounters a
cold glass of water.
Answer:
The postulates of the Kinetic Molecular Theory, KMT, are;
(1) In an ideal gas the molecules are in constant motion
(2) The collisions between molecules of gases are perfectly elastic
(3) The volume occupied by the molecules are negligible
(4) The temperature of the gas is directly proportional to its kinetic energy
(5) The intermolecular forces in the gas are negligible
According to the KMT, gaseous water vapor molecules are in constant motion and move at a speed that depends on their temperature. The intermolecular forces between the molecules are negligible and when they collide with the cold glass, they lose temperature to the glass, thereby reducing their temperature, kinetic energy and therefore, their speed is reduced.
The increasingly temperature of the water vapor coming in contact with the cold glass gives rise to reduced speed of the cooled gas molecules, thereby causing them to move closer together after having elastic collisions and to cluster with tiny particles in the air, to form tiny droplets
The rapid cooling on the cold glass surface causes the droplets to form rapidly on the cold glass surface which makes them visible as condensed water on the surface of the cold glass of water
Explanation:
6
A light bulb changes
???? energy into
and ??? energy
The
??? energy is useful energy, and the heat energy is ??
energy
Explanation:
electrical energy into heat energy
electrical , thermal
a. What is the physical quantity in which force is divided by area called?
Any guess 50 pts + brainlist if correct
Answer:
pressure
Explanation: pressure=force/area
Answer:
The quantities that can be measured are called physical quantities.....
1. Imagine a bowling ball with a mass of 5,0 kg that is dropped from a height of 100m,
a. At the moment the bowling ball is dropped it is at a height of 100m, What is its
potential energy?
b. At the moment the bowling ball is dropped, it is not yet moving. Therefore, its
kinetic energy is what?
c. What is the total of both potential and kinetic energy?
a.
Given,
height (h) = 100m
mass (m) = 5kg
acceleration due to gravitation (g) = 9.8ms^-2
Potential energy
= mgh
= 5kg × 9.8ms^-1 × 100m
= 4900 kgm²s^-2
= 4900 J
b.
Since the ball is not moving yet, its kinetic energy is 0.
c.
The total of potential and kinetic energy at every point of the journey is same, i.e., 4900 J.
Is velocity ratio of a machine affected by applying oil on it?Explain with reason.
Answer:
It depends upon SAE No. of oil. (SAE means Society of Automotive Engineers). However, it usually does protect against friction.
Explanation:
If we use very viscous oil, it does not reach all the parts. Very thin oil will flows away easily and gets wasted. Grease is used in such cases. It is generally used around ball-bearing. Normal grease or oil is never used where there is high pressure, high temperature and high speed. Special lubricants are used in such cases. In cold season the oil becomes thick and in hot season it becomes thin. Therefore selection of lubrication also depends on the season. It is always advisable to refer operating manual of the equipment before selecting the lubricant.
The intensity of friction depends on following factors:
i) The area involved in friction.
ii) The pressure applied on the surfaces.
Force = Pressure ´ Area Frictional force will increase, if the area of contact will increase or if pressure applied on the surface increased.
what will happen to the gravition force between two bodies if the distance between them is halved keeping their masses constant
Answer:
The new force will be 4times the original
Muốn đun sôi 200g nước từ 30 độ cần cung cấp nhiệt lượng bao nhiêu :
Answer:
cần cung cấp 70 độ vì nước sôi ở 100°C
Explanation:
PLS PLS PLS HELP ME! IT IS DUE IN TEN MINUTES
For his next stunt, Super Dave (80 kg) starts running at 2.00 m/s, then slides down a frictionless slide which is elevated 12.0 m above the ground, then slides across the rough asphalt ground to slow him to a stop (ouch!) He slides across the asphalt for 8.00 m before coming to a stop. What is the coefficient of friction between Super Dave and the ground?
Answer:
Preface to Students: Welcome to Physics! iv. 1 Motion. 1. 1-1 Speed, Velocity, and. Acceleration. 1. 1-2 Free Fall. 8. 2 Vectors and Projectiles.
257 pages·3 MB
Explanation: I hope this helpssss!!!
b) A force is represented in magnitude and direction as (6N, 250degrees. Find both the vertical and horizontal components of the force.
Answer:
Explanation:
To find the horizontal component, the x component specifically, use the formula:
[tex]V_x=Fcos\theta[/tex] and for the vertical component, the y component, use the formula:
[tex]V_y=Fsin\theta[/tex]
where F is the magnitude of the force and theta is the angle in degrees.
For the x-component:
[tex]V_x=6cos250[/tex] so
[tex]V_x=-2.1[/tex] and depending upon whether this is a displacement vector or a velocity vector, the label would be meters/feet or m/s, respectively.
For the y-component:
[tex]V_y=6sin250[/tex] so
[tex]V_y=-5.6[/tex]
Name the type of relationship between current and potential difference for a resistor at constant temperature. [
The current flowing through a resistor at a constant temperature is directly proportional to the potential difference across it. This is called Ohm's law
An object is thrown with velocity 7.1 m s-1 vertically upwards on the Moon. The
acceleration due to gravity on the Moon is 1.62 ms? What is the time taken for the object to return to its starting point?
A 3.5 s
B 4.4 s
C 6.5 s
D 8.8 s
Answer:D
Explanation:
Convert 1nanosecond in to its SI init
Convert 1nanosecond in to its SI init
In SI units, nano is 1000th part of micro which in turn is 1000th part of mini which in turn is 1000th part of main unit. Now, when you affix nano to any unit, here in case, second, it means that you are referring to 1000th part of 1000th part of 1000th part of second or in short, 1000000000th(10^9) part of a second.
In SI units, nano is 1000th part of micro which in turn is 1000th part of mini which in turn is 1000th part of main unit. Now, when you affix nano to any unit, here in case, second, it means that you are referring to 1000th part of 1000th part of 1000th part of second or in short, 1000000000th(10^9) part of a second.So to convert nanosecond into second, just multiply the nanosecond with 0.000000001 or (10^-9)
What acceleration is produced on a mass of 200g, when a force of 10N is exerted on it?
Answer:
f=ma......10N=0.2a....=50m/s
Answer:
here,
force = mass× acceleration
10 = 0.2 kg × a
or, 10/0.2=a
or, a = 50km/h^2
is the required ans .
A object of mass 200kg is pushed from rest by a force of 500N along a horizontal plane for 5.0 seconds. Calculate the acceleration of the object
Answer:
force=mass×acceleration
hence
acceleration is given by force÷mass
(500÷200)*5=12.5
Question in the picture please help me...
Show all steps please....
Answer: i)A to B : (ice) freezing
ii) B to C (water) boiling
C to D (steam) evaporating
explanation: 0° is the freezing point of water when temperature increases from 0° the water starts melting. As 100° is the boiling point of water so at 100° the water completely melts and it starts boiling during boiling water changes into steam(water vapour) and it evaporates
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 car moves at a speed of 40km/h. it is stopped by applying brake which produce a uniform acceleration of-0.5m/s^2. how much distance will it move before coming to stop ? plz its urgent
Answer:
Explanation:
I answered this in question #24313516
What is the purpose of the lab the importance of the topic and the question you are trying to answer?
perpose of lab is to store apparatus and do some experiment
Helps someone to know the exert lengh of something
