Careers360 Logo
NEET Official Answer Key 2024 by NTA Out at exams.nta.ac.in

Mass And Density Of Earth - Practice Questions & MCQ

Edited By admin | Updated on Sep 25, 2023 25:23 PM | #NEET

Quick Facts

  • 6 Questions around this concept.

Solve by difficulty

Does the variation in "g" due to the Earth's rotation affect the weight of objects?

 

Concepts Covered - 1

Mass and Density of Earth
  • Mass of earth-

Using Newton’s law of gravitation we can estimate the mass of the earth

M=\frac{gR^{2}}{G} \simeq \; 10^{25}kg

M\rightarrow mass of earth

G\rightarrow Gravitational constant

 

  • Density of earth

As g=\frac{4}{3}\pi \rho \, GR

Where \rho \rightarrow density of earth

So \rho =\frac{3g}{4\pi GR}

 

\rho =5478.4\; kg/m^{3}

  • Inertial mass

Also known as the mass of material of body which measures its inertia.

From  Newton’s second law of motion

F=m_{i}a

So m_{i}=\frac{F}{a}

Where 

m_{i}\rightarrow inertial mass

F\rightarrow external force

a\rightarrow\: acc^{n}

  1.   Gravity has no effect on inertial mass.

  2.   Inertial mass is independent of size, shape, and state of the body.

 

  • Gravitational Mass-

It is mass which determines the gravitational pull acting upon it.

Let F= gravitational pull on a body of mass 

applying Newton’s law of gravitation

We have F=\frac{GMm_g}{R^2}

So we get m_g=\frac{F}{GM/R^{2}}=\frac{F}{I}

Where m_g= Gravitational mass

I\rightarrow Gravitational field intensity

            Tip-Spring balance measure gravitational mass.

  • Mass (m)

 

  1. It is the quantity of matter contained in the body.

  2. Its SI unit- Kg

  3. Its dimension is [M] 

  4.  It is a scalar quantity.

  5. It Can never be zero

  6. Its value does not change with g.

 

  • Weight (W)

  1. It is an Attractive force exerted by the earth on anybody.

  2. S.I. Unit: Newton or Kg - wt 

  3. Dimension-[MLT^{-2}] 

  4. It is a vector quantity

  5. It changes its value according to the value of g

  6.  At \infty and at the centre of earth g = 0, So W is equal to zero there.

Study it with Videos

Mass and Density of Earth

"Stay in the loop. Receive exam news, study resources, and expert advice!"

Get Answer to all your questions

Back to top