An astronaut experiences weightlessness in a space satellite. It is because
- the gravitational force is small at that location in space
- the gravitational force is large at that location in space
- the astronaut experiences no gravity
- the gravitational force is infinitely large at that location in space
The Correct Option is C
Solution and Explanation
ie., $w=m g$
$w=m \times 0=0$
Top Questions on Gravitation
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- The value of \( g \) at height \( h \) above Earth's surface is \( \frac{g}{\sqrt{3}} \). Find \( h \) in terms of the radius of the Earth.
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- Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R):
(A) A simple pendulum is taken to a planet of mass and radius, 4 times and 2 times, respectively, than the Earth. The time period of the pendulum remains same on earth and the planet.
(R) The mass of the pendulum remains unchanged at Earth and the other planet.
In light of the above statements, choose the correct answer from the options given below:- JEE Main - 2025
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A small point of mass \(m\) is placed at a distance \(2R\) from the center \(O\) of a big uniform solid sphere of mass \(M\) and radius \(R\). The gravitational force on \(m\) due to \(M\) is \(F_1\). A spherical part of radius \(R/3\) is removed from the big sphere as shown in the figure, and the gravitational force on \(m\) due to the remaining part of \(M\) is found to be \(F_2\). The value of the ratio \( F_1 : F_2 \) is:
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Questions Asked in KEAM exam
For the reaction:
$3Fe_{(s)} + 2O_2{(g)} \rightarrow Fe_3O_4{(s)}$
$\Delta H = -1650\,\text{kJ mol}^{-1}$, $\Delta S = -600\,\text{J K}^{-1} \text{mol}^{-1}$ at $300\,\text{K}$. What is the value of free energy change for the reaction at $300\,\text{K}$?
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- Thermodynamics
- For the reaction: $$ 2A + B \rightarrow 2C + D $$ The following kinetic data were obtained for three different experiments performed at the same temperature: $$ \begin{array}{|c|c|c|c|} \hline \text{Experiment} & [A]_0 \, (\text{M}) & [B]_0 \, (\text{M}) & \text{Initial rate} \, (\text{M/s}) \\ \hline \text{I} & 0.10 & 0.10 & 0.10 \\ \text{II} & 0.20 & 0.10 & 0.40 \\ \text{III} & 0.20 & 0.20 & 0.40 \\ \hline \end{array} $$ The total order and order in $[B]$ for the reaction are respectively:
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- Torque on a coil carrying current \( I \) having \( N \) turns and area of cross section \( A \) when placed with its plane perpendicular to a magnetic field \( B \) is:
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- Simplify the following expression: \[ \cos 18^\circ \cos 42^\circ \cos 78^\circ. \] The simplified form is:
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Concepts Used:
Gravitation
In mechanics, the universal force of attraction acting between all matter is known as Gravity, also called gravitation, . It is the weakest known force in nature.
Newton’s Law of Gravitation
According to Newton’s law of gravitation, “Every particle in the universe attracts every other particle with a force whose magnitude is,
- F ∝ (M1M2) . . . . (1)
- (F ∝ 1/r2) . . . . (2)
On combining equations (1) and (2) we get,
F ∝ M1M2/r2
F = G × [M1M2]/r2 . . . . (7)
Or, f(r) = GM1M2/r2
The dimension formula of G is [M-1L3T-2].