Answer:The velocity of the train is 3.84m/s
Explanation:
According to the Doppler effect, if the source is moving towards you then the apparent frequency of the sound emitted by the source is higher and if the source is moving away from you then the apparent frequency of the sound emitted by the source is smaller.
This is given by:
fo = V +-Vo/ V +-Vo × source
Where fo= observed frequency
V= velocity of sound
Vo= vo it of the observer
fsource= frequency the source
Given:
Observed frequency of the approaching train fo1= 452Hz
The observed frequency of train= fo2= 442Hz
Velocity of sound= 334m/s
Velocity of source=?
Train approaching the observer is given by:
fo1= V/(V - Vs)× source ...eq1
Train passes the student is given by:
fo2= V/(V - Vs)×source ...eq2
Divide eq1 by eq2
452/442 = (343+Vs)/(343 - Vs)
1.02 =(343+Vs)/(343 -Vs)
Cross multiply
1.02(343- Vs) = 343 + Vs
350.76 - 1.02Vs = 343 + Vs
Collecting like terms
350.76 -343= 1.02Vs+ Vs
7.76 = 2.02Vs
Vs= 7.76/2.02
Vs= 3.84m/s
Yes, it can change states of matter from heat. Like ice, ice changes it’s state of matter from the temperature it is in, which causes it to turn into a liquid.(another form of matter) Again with heat, if water is boiled to a certain temperature it converts to a gas. Now with cold. If water is at such a coke temperature it will turn to ice, a form of matter. Now when a gas is cooled down, the atoms comprising the gas have less energy to move around.
1. Ca → Element
2. Proton → positive
3. H2O → compound
4. Fission → nuclear decay
5. Fusion → Nuclear synthesis
6. η → Neutron
7. e → electron
8. Atomic number → no of protons in nucleus.
Explanation
1. Ca (Calcium):
Calcium is an element with the atomic number of 20. It is an alkaline earth metal. The 99% of calcium is found in our bodies, in bones, teeth.
2. Proton:
Proton is a subatomic particle and it holds the positive charge. Proton is present in the nucleus of the atom.
3. H2O (water):
Water is a chemical compound and it's chemical formula is H2O. It's called compound as it contains 2 hydrogen and 1 oxygen atoms bonded together through the covalent bond.
4. Fission:
Fission is a process in which large massive unstable nucleus splits into the smaller, less heavier and stable nuclei. The energy is re;eased in the form of radiations during this process. It's called as the radioactive decay.
5. Fusion:
Fusion is opposite of the fission reaction. As in this case the two nuclei combines to form a single large nucleus. That's why it is a nuclear synthesis process.
6. η neutron:
Neutron is a subatomic particle and it is a neutral particle which is located inside the nucleus. n is a symbol used for the neutron.
7. e Electron:
The symbol for electron is e. It's a subatomic particle with negative charge. It is found in the orbits around the nucleus.
8. Atomic Number:
Atomic number is defined as the number of protons in the nucleus of an atom. IT is represented by Z.
Answer:
(A) 3.1 m/s
(B) 2.0 s
Explanation:
At the minimum speed, the force of gravity equals the centripetal force.
mg = m v² / r
v = √(gr)
v = √(9.8 m/s² × 1.0 m)
v = 3.1 m/s
The time is the circumference divided by the speed.
t = (2π × 1.0 m) / (3.1 m/s)
t = 2.0 s
Answer:
22 degree
Explanation:
Angle of incidence, i = 30 degree
the refractive index of water with respect to air is 4/3.
As the ray of light travels from rarer medium to denser medium, that mean air to water, the refraction takes place.
According to Snell's law,
Refractive index of water with respect to air = Sin i / Sin r
Where, r be the angle of refraction
4 / 3 = Sin 30 / Sin r
0.75 = 2 Sin r
Sin r = 0.375
r = 22 degree
Thus, the angle of refraction is 22 degree.
