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Ask QuestionPosted by Shubham Ojha 4 years, 1 month ago
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Posted by Harsha C.D 4 years, 1 month ago
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Ruhi Rao 4 years, 1 month ago
Posted by Harsha C.D 4 years, 1 month ago
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Ruhi Rao 4 years, 1 month ago
Posted by Royal Thakur ? 4 years, 1 month ago
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Ruhi Rao 4 years, 1 month ago
Posted by Ahamed Anas 4 years, 1 month ago
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Gaurav Seth 4 years, 1 month ago
Given that the parallax angle, θ = 1° 54' = 114'
114' = 114× 60'' = 6840''
We know that 1'' = 4.85 × 10-6 rad
Therefore 1° 54' = 6840'' × (4.85 × 10-6 ) rad
θ = 3.32×10-2 rad
Given the diameter of earth, b = 1.276 × 107 m
Hence the distance of the moon from the earth = 3.843 × 108 m
Posted by Dεερακ Ȿιηɠꜧ 4 years, 1 month ago
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Posted by Aman Sahni 4 years, 1 month ago
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Posted by Anas Shaikh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
Linear Expansion means expansion in length due to increase in temperature. Linear expansion means fractional change in length i.e. how the length is changing with respect to original length.
As we can seefrom above images the length has been increased from
l to l+Δl.
Coefficient of Linear Expansion is a parameter which tells us how the size of the object changes with change in temperature. It is defined as degree of linear expansion divided by the change in temperature.
- If the solid is in the form of long rod, then for small change in temperature, ΔT, the fractional change in length, Δl/l, is directly proportional to ΔT.
Mathematically can be written as:-
Where αl= the coefficient of linear expansion
It is denoted by αl
- It is characteristic of the material of the rod.It varies for different substance.
Posted by Mithun G Kumar 4 years, 1 month ago
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Gaurav Seth 4 years, 1 month ago
Let us consider a particle travel with constant speed from A to B in a circular path of radius r in a short time Δt
making an angular displacement Δθ as shown in figure.
distance S travelled is the arc length AB and it is given by, S = v×Δt ..................(1)
Arc distance S also written geometrically as, S = r×Δθ ...........................(2)
from (1) and (2), we write , Δθ/Δt = v/r ...............(3)
Eqn.(3) is rate of angular displacement or angular velocity.
For small angular displacement made in short time Δt, we can write = dθ/dt = v/r ......................(4)
In right side figure, velocity vectors at A and B are drawn by merging their initial points.
The angle between these vectors also Δθ.
from the right side figure, we write, sin (Δθ/2) = (Δv/2) / v or Δv/2 = v sin(Δθ/2) .................(5)
For small angle Δθ, eqn.(5) is written as, Δv/2 = v Δθ/2 or Δv/Δθ = v or dv/dθ = v .....................(6)
using eqn.(4) and eqn(6), acceleration directed towards centre, dv/dt = ( dv/dθ ) (dθ/dt) = v×(v/r) = ( v2 / r )
If m is mass, then force F = mass×acceleration = m×(v2 / r )
Posted by Bhumi Shukla 4 years, 1 month ago
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Posted by Sameer Yadav 4 years, 1 month ago
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Ruhi Rao 4 years, 1 month ago
Posted by Bhumi Shukla 4 years, 1 month ago
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Posted by Aadya Singh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
Normally each physical quantity requires a unit or standard for its specification, so it appears that there must be as many units as there are physical quantities. However, it is not so. It has been found that if in mechanics we choose arbitrarily units of any three physical quantities we can express the units of all other physical quantities in mechanics in terms of these. So, length, mass and time are chosen as base quantities in mechanics because
(i) Length, mass and time cannot be derived from one another, that is these quantities are independent.
(ii) All other quantities in mechanics can be expressed in terms of length, mass and time.
Sulinder Kumar 4 years, 1 month ago
Posted by Aadya Singh 4 years, 1 month ago
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Posted by Dεερακ Ȿιηɠꜧ 4 years, 1 month ago
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Posted by Royal Thakur ? 4 years, 1 month ago
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Posted by Payal Rana 4 years, 1 month ago
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Chandan . 4 years, 1 month ago
Gaurav Seth 4 years, 1 month ago
Gravity is a force that attracts a body towards the centre of the earth, or towards any other physical body having mass.
History of Gravity
- In 1687, Sir Isaac Newton first discovered gravity. While sitting under an apple tree, he noticed an apple falling down. Then he tried to figure out why the apple instead of going up or left or right, came down. In this situation, there was clearly an unknown force at play, that force is what Newton called gravity and his theory is called Newton’s law of Universal Gravitation.
- Later in the early 20th century, Albert Einstein developed a whole new idea about gravity. According to him, gravity is the warping of space and time.
Posted by Saloni Chaudhary 4 years, 1 month ago
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Sia ? 3 years, 5 months ago
Posted by Shashwat Singh 4 years, 1 month ago
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Shashwat Singh 4 years, 1 month ago
Posted by Royal Thakur ? 4 years, 1 month ago
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Posted by Shashwat Singh 4 years, 1 month ago
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Shashwat Singh 4 years, 1 month ago
Posted by Shashwat Singh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
Yes magnitude of a physical quantity change with change in system of units.
If Length = 14 km. here magnitude is 14 and unit is km
As we know 1 km = 1000 m.If we change kilo meter to meter. then 14 km = 14000 m.
So here magnitude is 14000 and unit is meter. So if we change unit then magnitude also changes.
Posted by Shashwat Singh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
A system of units in which derived units are obtained from a set of fundamental or base units by way of simple multiplication or division or both such that no numerical factors comes up is called coherent system of units, e.g., S.I.
Posted by Shashwat Singh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
Astronomical unit is the average distance between the earth and the sun. It is near 1.5 x 1015 m Light year the distance traveled by light in one year. whereas 1 parsec is about 3.26 Light year
Posted by Shashwat Singh 4 years, 1 month ago
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Yogita Ingle 4 years, 1 month ago
One parsec is defined as the distance at which an arc of length one astronomical unit subtends an angle of one second of an arc .
1 parsec = 3.08 x 1016m.
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