Answer:
Physical Changes :- The substance in which no new substance is formed are called physical changes.
The molecular composition of the substance are totally same.
For example :- Crushing a mineral into powder.
Which law states that absolute zero cannot be reached?
Write down the role played by four digestive juices in digestion and the
organs which secrete them.
Answer:
Explanation:Digestive juices secreted by various organs such as salivary glands in the mouth, stomach, liver and pancreas help in the process of digestion of food. Saliva secreted by the salivary glands in the mouth aids in the breakdown of starch present in the food to simple sugar
một oto đang chạy với vận tốc là 10m/s thì tăng tốc và chuyển động nhanh dần đều sau 20s thì đạt vận tốc 14m/s
a) tính gia tốc của xe
b) tính vận tốc xe sau 40s kể từ khi tăng tốc và quãng đường xe đi được trong thời gian đó
a) gia tốc = vf-vi / t
a = 14-10 / 20
a = 0,2ms⁻²
b) dưới dạng a = Δv / t
v = lúc
v = 0,2 × 40
v = 8ms⁻¹
như v = d / t
do đó d = vt
d = 8 × 40
d = 320m
hãy đánh dấu là trí óc nhất
The velocity ratio of a pulley system is 4. What does it means
Answer:
Velocity ratio = distance travelled by effort / distance travelled by load. Which is equal to effort arm / load arm. When velocity ratio (VR) is 4, the effort arm is greater than load arm.
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
A glass rod acquires charge by rubbing silk cloth. The charge on the glass is due to:
(a) Friction
(b) Conduction
(c) Induction
(d) Radiation
Answer:
(a)Friction
Explanation:
It is due to friction as you are rubbing the glass rod with silk cloth
as friction occurs when 2 surfaces are rubbed against each other
Therefore it is charging by friction
if you rub a ballon with wool or duster it can charge it negatively where do these extre charge come from?
Answer:
The electrons come from the free electrons in wool which contains moisture or other forms of additives that creates impurity centers which causes the wool to be electrically conductive
Explanation:
Wool which is mixed with certain substances, conducts electricity in a manner similar to the wool-water system that give rise to centers of impurities where electrical conduction takes place
The ability to conduct electricity is related to the presence of free electrons on a material. Therefore, when a balloon, which is an insulator, is rubbed with wool, some of the mobile electrons on wool, which is also an insulator without the presence of substances that aid its electrical conductivity, are transferred to the balloon, thereby making the balloon to be negatively charged
1. Which of the following are good cross-training workouts for walking
Swimming
Biking
Basketball
All of the above
Answer:
All of the above is the answer
A cricket ball of mass 800g has momentum of 20 kg m/sec . Calculate velocity of ball
Answer: 25 m/s
Explanation:
1. rearrange equation p = mv to find v
2. v = p/m - then convert 800 g into kg (= 0.8 kg)
3. plug in p and m - v = 20 / 0.8 = 25 m/s
Answer:
V= 25m/s
Explanation:
Mass=800g
Momentum=20kgm/s
V= ?
Convert 800g to kg
800/1000 = 0.8kg
Momentum=mass× Velocity
Momentum/Mass = Velocity
20/0.8 =25m/s
The spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum. have wavelengths that are longer than normal. have a higher intensity in the red part of the spectrum. have wavelengths that are shorter than normal.
have a higher intensity in the red part of the spectrum
Because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum
Most galaxies' spectra have been redshifted, which means that their spectral lines are now pushed away from their normal or rest wavelengths and towards longer wavelengths. When an object travels away from an observer, the Doppler effect causes the shift phenomenon.
The Big Bang hypothesis and the concept of the expanding universe, show that galaxies are moving away from us, observed from the redshift lines.
The waves' apparent wavelengths shift as a result, changing the color of light waves or the pitch of sound waves.
Hence, because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum.
To learn more about the Doppler effect, here:
https://brainly.com/question/28106478
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If a force of 1250 N acts on an area of 25 metres squared, what will be the pressure acting on the surface? Show your working as well.
Answer: 50 Pa
Explanation:
Pressure = Force/Area
Pressure = N/m^2
Pressure = 1250/25
Pressure = 50
Pressure = 50 Pa
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Answer:
50 pascal
Explanation:
Force=1250N
Area=25m^2 [ pressure=force/area]
P=F/A
1250/25=50
please help urgent have you ever seen the old “Pull the tablecloth out from under the dishes” trick? Use Newton’s 1st Law to explain the following:
a. In this trick, are the dishes “objects in motion,” or “objects at rest?”
b. If the dishes end up staying on the table, was an UNBALANCED FORCE applied to them? How do you know?
Answer:
I kinda dont remember the 1st law so search it up on
and it should tell u , but if u need any help from the
How effectiveness of a small force is increased when action area of force is
reduced?
Answer:
The force is proportional to the area, for if we increase the area but keep the number of molecules per cubic centimeter the same, we increase the number of collisions with the piston in the same proportion as the area was increased.
Explanation:
more area =more space = more free for molecules = less pressure = less force.
a box being pushed with a force of 85N right slides along the floor with a constant speed of 0.5m/s. What is the force of sliding friction on the box?
Answer:
[tex]85\; \rm N[/tex].
Explanation:
The box is sliding with a constant speed in a fixed direction (to the right.) In other words the velocity of this box is constant. Hence, this box would be in a translational equilibrium. The acceleration of this box would be zero.
By Newton's Second Law of motion, the net force on this box would be [tex]0[/tex]. In other words, forces on this box are balanced.
The question is asking for the size of the friction on the box. Assuming that the floor is horizontal. The friction on this box would also be horizontal,
The only other force that could balance that friction would be the [tex]85\; \rm N[/tex] push to the right. The direction of this push is horizontal (to the right.) Hence, the entirety of that [tex]85\; \rm N\![/tex] would be in the horizontal direction.
Thus, forces on this box in the horizontal direction would be:
The [tex]85\; \rm N[/tex] push to the right.Friction that opposes the rightward motion of the box (that is, to the left.)Since these two forces must balance each other, the size of the friction would also be [tex]85\; \rm N[/tex].
what do you mean by scattering of light
Answer:
Scattering of light is the phenomenon in which light rays get deviated from its straight path on striking an obstacle like dust or gas molecules, water vapours etc. Scattering of light gives rise to many spectacular phenomena such as Tyndall effect and the “red hues of sunrise and sunset”.
an electron is moving at 3.6 x 10^3 m/s. a photon with what wavelength would have the same momentum????
Answer:
The wavelength of the photon that would have the same momentum as the electron is 202.2180996 nm
Explanation:
The velocity of the electron, v = 3.6 × 10³ m/s
The momentum of an electron, [tex]p_e[/tex] = m × v
Where;
v = The mass of the electron = 9.109 × 10⁻³¹ kg
∴ [tex]p_e[/tex] = 9.109 × 10⁻³¹ kg × 3.6 × 10³ m/s = 3.27924 × 10⁻²⁷ kg·m/s
According to the de Broglie equation, the momentum of a photon, p, is given as follows;
p = h/λ
Where;
h = 6.63 × 10⁻³⁴ J·s
λ = The wavelength of the photon
∴ λ = h/p
According to the question, we have;
p = [tex]p_e[/tex] = 3.27924 × 10⁻²⁷ kg·m/s
∴ λ = 6.63 × 10⁻³⁴ J·s/(3.27924 × 10⁻²⁷ kg·m/s) = 2.02180993 × 10⁻⁷ m
The wavelength of the photon, λ = 2.02180993 × 10⁻⁷ m = 202.2180993 × 10⁻⁹ m = 202.2180993 nm.
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 is Newton's first law of motion?
EXPLAIN WITH SOME EXAMPLES
Answer:
The tendency of undisturbed objects to stay at rest or to keep moving with the same velocity is called inertia. This is why, the first law of motion is also known as the law of inertia.
Example.: A ball at rest on the ground continues to be at rest unless someone kicks it or any external force acts on it.
Explanation:
I hope this will help you buddy
7) A ball is thrown upward at an initial velocity of 8.2 m/s, from a height of 1.8 meters above the ground. The height of the ball h, in metres can be represented, after t seconds, is modelled by the equation h = –4.8t² + 8.2t + 1.8. (a) Determine the height of the ball after 1.7 seconds.
Answer:
8392
Explanation:
d=s/t
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
Examples of a/an _______ observation are 37 m, 9.37 s, and 100 mph.
These are exaxmples of a quantitative observation.
Measuring is the expression of an observed quantity in a number with a relevant unit that can be compared with other values of the same quantity.
It is not limited to physical quantities, but extends to a quantitative description of the whole of reality. Measurements are usually quantitative observations, and their results are expressed in
numerical values, and unitsLearn more about quantitative observations in https://brainly.com/question/12042148.
Summary of set.........
Answer:
Set for what? did U finish the question?
Which of the following phenomena can be used to support the particle theory of light? Select all that apply.
The Photoelectric Effect
Polarization
Interference Patterns
Refraction
Reflection
Numerical Problems:
a. A man runs 1200 m on a straight line in 4 minutes. Find his velocity.
can anyone tell me with process
[tex]\boxed{\sf Velocity=\dfrac{Displacement}{Time}}[/tex]
[tex]\\ \sf\longmapsto Velocity=\dfrac{1200}{240}[/tex]
[tex]\\ \sf\longmapsto Velocity=5m/s[/tex]
Suppose that people living near a particular​ high-voltage power line have a higher incidence of cancer than people living farther from the power line. Can you conclude that the​ high-voltage power line is the cause of the elevated cancer​ rate? If​ not, what other explanations might there be for​ it? What other types of research would you like to see before you conclude that​ high-voltage power lines cause​ cancer?
Complete Question
Complete Question is attached below
Answer:
a)Option B
b)Option B
Explanation:
a)
Without any confirmation it will be utterly wrong to conclude that high power voltage is the reason for the elevated cancer cases
Therefore
Option B
b)
The High Concentration of cells volume in a part of the Body is what causes Cancer
Therefore
Option B
A motorcycle starts from rest and gains a velocity of 40m/s in 8 seconds. Find (i) acceleration and (ii) distance travelled by the motorcycle.
• Initial velocity (u) = 0 m/s
• Final velocity (v) = 40 m/s
• time (t) = 8s
Acceleration :[tex]\implies \sf a = \dfrac{\Delta v}{ t} \\ [/tex]
[tex]\implies \sf a = \dfrac{v - u}{ t} [/tex]
[tex]\implies \sf a = \dfrac{40 - 0}{ 8} [/tex]
[tex]\implies \sf a = \dfrac{40}{ 8} [/tex]
[tex]\implies \bf a = 5 \: {ms}^{ - 2} [/tex]
• Distance travelled by the motorcycle:[tex] \longrightarrow \sf {v}^{2} - {u}^{2} = 2as \\ [/tex]
[tex]\longrightarrow \sf {(40)}^{2} - {(0)}^{2} = 2 \times5 \times s \\ [/tex]
[tex] \longrightarrow \sf 1600 = 10s[/tex]
[tex]\longrightarrow \sf s = \dfrac{1600}{10} [/tex]
[tex]\longrightarrow \bf s = 160 \: m[/tex]
The Weight of an object is more at pole and less at equator of the earth. Give reason
The Weight of an object is more at pole and less at equator of the earth because the distance of the pole is less than the distance of the equator from the centre of the earth.
If the N pole of a magnet is brought near to an unmagnetized iron, nail, then the nail becomes
Answer:
The nail also magnatized .
what does a resistor in an electrical dp
Answer:
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
Explanation:
Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resistors are also implemented within integrated circuits.
The electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude. The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component.
can someone pls help me calculate this?
Answer:
10N is the answerrrerreer
Answer:
f= 100N
Explanation: F=m×(v₀-vf/t)
=0.05ₓ(200-0/0.1)
=0.05ₓ2000
=100N
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