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
Based on its location on the periodic table, which element is the best
electrical insulator?
A. Iron (Fe)
O B. Sulfur (S)
O C. Calcium (Ca)
D. Silver (Ag)
Answer:
B
Explanation:
Nonmetal is better insulator than metals
Answer:
B
Explanation:
Just took the quiz.
A certain superconducting magnet in the form of a solenoid of length 0.28 m can generate a magnetic field of 7.0 T in its core when its coils carry a current of 80 A. The windings, made of a niobium-titanium alloy, must be cooled to 4.2 K. Find the number of turns in the solenoid.
Answer:
The number of turns in the solenoid is 19506.
Explanation:
Length of solenoid, L = 0.28 m
Magnetic field, B = 7 T
Current, I = 80 A
Let the number of turns is N.
The formula used to find the magnetic field is
[tex]B = \frac{\mu 0N I}{L}\\\\7 = \frac{4 \times 3.14\times 10^{-7}\times N\times 80}{0.28}\\\\N = 19506[/tex]
A car is running uniformly with the velocity of 72km/h3, what is its acceleration?
Answer: a =0
Explanation:
Which of the following is occurring while a satellite is in orbit around Earth? O It is continuously pulling away from Earth It is continuously falling toward the surface of Earth. It stays in a constant speed orbit where it was oriented from the start. It stays in the same orbit orientation traveling at variable speeds.
AnswerIt is continuously falling towards the surface of the earth
Explanation:
since gravity from earth is the thing that keeps it constantly in orbit
Which statement about the ocean is true?
No evaporation or precipitation in the water cycle occurs over the ocean.
Most evaporation and precipitation in the water cycle occur over the ocean.
All evaporation and precipitation in the water cycle occur over the ocean.
Evaporation, but not precipitation, in the water cycle occurs over the ocean.
Answer:
most evaporation and precipitation in the water cycle occus over the ocean
The option Most evaporation and precipitation in the water cycle occur over the ocean. is the correct answer
(Q008) Magnetic anomalies are a. found only on the seafloor. b. measured with an instrument called an inclinometer. c. defined as the angle between which a compass needle points and the longitude at that point. d. places where the magnetic field strength is either greater or less than the expected strength.
Answer: D. places where the magnetic field strength is either greater or less than the expected strength.
Explanation:
Magnetic anomaly refers to the change in the magnitude of the magnetic field of the Eatth with respect to the location's expected value.
Magnetic anomalies are places where the magnetic field strength is either greater or less than the expected strength. Therefore, the correct option is D.
A rocket blasts off. In 10.0 seconds it is at 10,000 ft, traveling at 3600 mph. Assuming the direction is up, calculate the acceleration.
Answer:
Explanation:
Givens
t = 10 seconds
vi = 0
vf = 3600 mph
a = ?
d = 10000 feet
Formula
a = (vf - vi)/t
Solution
vf = 3600 mph * 1 hr / 3600 seconds * 5280 feet / 1 mile = 5280 ft / sec
a = (5280 - 0)/10
a = 528 ft/sec^2
Straight wire of indefinite length (transient) passed by an electric current of 5.0 A. The magnetic field generated around this conductor at point M is 50 μT. Thus the distance from the conductor to point M is:
A. 2π cm
B. 0.2π cm
C. 2.0 cm
D. 0.20 cm
Answer:
C. 2.0 cm
Explanation:
The magnetic field around the wire at point M is given by Biot-Savart Law:
[tex]B = \frac{\mu_o I}{2\pi R}[/tex]
where,
B = Magnetic field = 50 μT = 5 x 10⁻⁵ T
I = current = 5 A
μ₀ = permeability of free space = 4π x 10⁻⁷ N/A²
R = distance of point M from wire = ?
Therefore,
[tex]5\ x\ 10^{-5}\ T = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(5\ A)}{2\pi R}\\\\R = \frac{(2\ x\ 10^{-7}\ N/A^2)(5\ A)}{5\ x\ 10^{-5}\ T}\\[/tex]
R = 0.02 m = 2 cm
Hence, the correct option is:
C. 2.0 cm
Give reason.
b} String roller is an example of wheel and axel .Why?
Explanation:
string roller is called an example of wheel and axel because The thin rod which needs to be turned is called the axle and the wider object fixed to the axle, on which we apply force is called the wheel.
hence the we apply force on the roller and the string gets tight.
The needle in the following diagram rotates around a fixed point in the middle. Based on the information given, what way will the needle rotate when the current is applied?
Answer:
nods 40th anniversary rid off e 49en9 snns
A 45.0 kg student runs at a constant velocity up the incline 6 metres high. If the power output of the student is 1.50 x 103 W, how long does it take the student to run the 9.0 m along the incline?
Answer:
The time taken is 1.76 s.
Explanation:
mass of student, m = 45 kg
height, h = 6 m
power, P = 1500 W
Power is defined as the rate of doing work.
Work done in moving height is
W = m g h
Let the time is t.
P = m g h / t
1500 = 45 x 9.8 x 6 / t
t = 1.76 s
What the velocity from the graph given above?
Answer:
i think its 4 or 35
Explanation:
its in the middle of 40 and 30
Explain the effects of force giving example
Answer:
1) Can change the state of an object(rest to motion/ motion to rest):For example, pushing a heavy stone in order to move it. 2) May change the speed of an object if it is already moving. 4) May bring about a change in the shape of an object. For example, blowing air in balloon.
Explanation:
Effect of force Can change the state of an object(rest to motion/ motion to rest):For example, pushing a heavy stone in order to move it.
In isoelectric focusing gel electrophoresis a. there is a pH gradient that parallels the electric field gradient b. particular care must be taken to ensure the same pH along the length of the gel c. the electric current is allowed to fluctuate d. the electric circuits of the apparatus must be very well insulated
Answer:
a. there is a pH gradient that parallels the electric field gradient.
Explanation:
Gel electrophoresis is a technique used to separate DNA fragments according to their size. DNA samples are loaded in the wells and then electric current is applied to pull the DNA fragments out from the gel. Isoelectric gel electrophoresis is a process in which negatively charged DNA fragments are separated from the gel.
how do atoms lose electrons ?
Answer:
Explanation:
By being close to an atom that will gladly take the electrons being offered.
Suppose you are talking about Be. It is in the second column. It has two outer electrons that can be given away. It will not give away one of the two remaining electrons because they are too close to the + nucleus.
Along comes a Fluorine atom. It has 7 electrons in its outer ring. The chemistry of the situation allows it to take on one of the two electrons Be is offering. It is all a matter of charges and attractions.
Another Fluorine atom will take on the remaining electron from the Be. The outer ring cannot take on more than 1 electron, but that is enough
What will happen to the velocity and momentum of each ball when the small ball hits the heavier large ball?
The small ball will transfer its momentum to the heavier ball. Since the momentum gets conserved. The velocity will depend upon the mass of the balls.
What is the law of conservation of momentum?According to the law of conservation of momentum. The momentum of the body before the collision is always equal to the momentum of the body after the collision.
The momentum of the body is given by the product of the mass and velocity of the body.
According to the law of conservation of momentum
Momentum before collision =Momentum after collision
Hence the small ball will transfer its momentum to the heavier ball.
To learn more about the law of conservation of momentum refer;
https://brainly.com/question/1113396
the unit of force and pressure are called derived unit
Answer:
yes
Explanation:
because they can be derived in the form of base units
Describe the term of inertia with the respect of motion
Answer:
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
Explanation:
Motion can be defined as a change in the location (position) of a physical object or body with respect to a reference point.
This ultimately implies that, motion would occur as a result of a change in location (position) of an object with respect to a reference point or frame of reference i.e where it was standing before the effect of an external force.
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
Newton's First Law of Motion is also known as Law of Inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
The inertia of an object such as a truck is greatly dependent or influenced by its mass; the higher quantity of matter in a trailer, the greater will be its tendency to continuously remain at rest.
In conclusion, inertia is applicable to all physical objects.
The gravitational force of the two objects is 6.67x10-11N. Explain this statement.
Answer:
it means that the force of attraction between two object in gravitation is 6.67×10-11N
It means that the force of attraction between two object in gravitation is 6.67×10-11N.
What is the formula of mass in gravitational force?The formula is g = GM/r2, Where M is the mass of the Earth, r is the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant. G (without the subscripts) is the gravitational constant, and c is the speed of light.
What is the gravitational force between two objects?The gravitational force between two objects is proportional to their masses and inversely proportional to the square of the distance between their centers. joining the two centers of masses.
Learn more about gravitational force here: brainly.com/question/13010127
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20.In case the conductor is a heating appliance, then this energy(w) is converted into heat(H) i.e
A. w=H C. w=I2Rt
B. w=VIt D. all of above
Answer:
not sure just need points
Explanation:
a+b+c
can anyone please help me
Answer:its most likely c
Explanation:
25 POINTS 25 POINTS 25 POINTS 25 POINTS 25 POINTS
Assignment: Build an Electromagnet and a Motor Investigation
Electromagnet
1. How many paper clips did the wire wrapped around the nail just a few times pick up?
2. Which electromagnet design was most successful in picking up the most paper clips?
3. Would wrapping the wire more times around the nail make the electromagnet stronger or weaker?
4. What do you think the result would be if an iron nail that was much thicker was used?
5. What do you think would happen if a wooden stick was chosen as the core instead of the iron nail?
Motor
1. Describe the components that are necessary to make a motor run? What do they each provide? (example: battery provides voltage source)
2. Describe how the homemade motor makes mechanical energy from electrical energy.
3. What are three appliances in your house that use a motor that turns electrical energy into mechanical energy?
All the paper clips, coiled wire with nail and wrapping or coiling the wire more times are the correct answers.
All the paper clips will the wire wrapped around the nail just a few times pick up. A coiled wire with nail in the center is the electromagnet design which is most successful in picking up the most paper clips. Wrapping or coiling the wire more times around the nail make the electromagnet more stronger.
If an iron nail that was much thicker was used, it will make the magnet stronger that leads to strong electromagnetism. There are three main parts that is necessary for making a motor i.e. a rotor, a stator and a commutator.
These three parts use the attractive and repulsive forces of electromagnetism, causing the motor to spin continually as long as it receives a steady flow of electric current. Motors comprise of loops of wire in a magnetic field.
When current is passed through the loops, the magnetic field exerts a torque on the loops, which rotates the shaft that leads to the generation of electricity. Water pump, mixer and washing machine are three appliances in your house that use a motor that turns electrical energy into mechanical energy.
https://brainly.com/question/24278437
(a) What kind of energy is possessed by an aeroplane flying at a height of 10000 m?
Answer:
When the plane is rest position it possess potential energy. But when a aeroplane is flying at the height it possess kinetic energy. No matter what height is given.
5. Can you get the machine with efficiency 100% in practice? Why?
Answer:
No,
Explanation:
Efficiency of a machine is always less than 100% as output energy is always less than the input energy, because some energy is lost to overcome friction.
A person carries a box of 100 kg. What is the weight of the box? (g= 9.8 m/s2)
Answer:
980 newton
Explanation:
100×9.8 = 980
A bullet of mass of 50g is moving with the velocity of 200km/h .calculate the kinetic energy of the bullet .
Answer:
is 10³
Explanation:
cuz the formula of KE is 1/2mv²
covert 50g to kg first then plug in the formula
1/2 × 0.05 × 200 = 10³ J
A man has 60w bulbs and a 240w water heater in his apartment. If the bulbs and the water heater are switched on for four hours daily and the cost of electricity is N1.20 per KWh calculare his bill in 30 days
Answer: [tex]N43.2[/tex]
Explanation:
Given
Power consumption of bulb and water are [tex]60\ W[/tex] and [tex]240\ W[/tex]
If the Devices are on for four hours
Total power of devices [tex]60+240=300\ W[/tex]
Energy consumed for 4 hours is
[tex]\Rightarrow 300\times 4=1200 Wh\\\Rightarrow 1.2\ kWh[/tex]
For 30 days it is [tex]1.2\times 30=36\ kWh[/tex]
Cost for 30 days [tex]36\times 1.2=43.2\ N[/tex]
How can you say gravitational force is a field force
Answer:
because gravity pulled us in the land if there is no gravitational force there will not be field force too
Explanation:
hope it's will help you
(6). A car travels in a straight line from city A to city B at a speed of 60kmh-1
. Then return
from city B to city A along the original route at a speed of 40kmh-1
. The distance between
the two cities is 120 km. What is the average speed of the vehicle?
1. 30kmh-1
2. 45kmh-1
3. 48kmh-1
4. 60kmh-1
một hòn đá có khối lượng 5kg bay với vận tốc 72kg/h . động lượng của hòn đá là
Answer:
Momentum = 100 Kgm/s
Explanation:
Given the following data;
Speed = 72 km/h
Mass = 5 kg
To find the momentum of the stone;
First of all, we would have to convert the value of speed to meter per seconds.
Conversion:
72 km/h to m/s = (72 * 1000)/3600 = 20 m/s
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
Momentum = mass * velocity
Substituting the values into the formula, we have;
Momentum = 5 * 20
Momentum = 100 Kgm/s
