A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth?
- 48 N
- 32 N
- 30 N
- 24 N
The Correct Option is B
Solution and Explanation
\(w_{s}=mg_{s}=72\,N\)
\(w_{h}=mg_{h}=\frac{mg_{s}}{\left(1+\frac{h}{R}\right)^{2}}\)
\(=\frac{72\,N}{\left(1+\frac{\frac{R }{2}}{2}\right)}\)
\(=\frac{72}{\frac{9 }{4}}\)
\(w_{h}=32\,N\)
Top Questions on Gravitation
- At a height \( h \) above the Earth's surface, the acceleration due to gravity becomes \( \frac{g}{\sqrt{3}} \). What is the value of \( h \) in terms of the Earth's radius \( R \)?
- MHT CET - 2025
- Physics
- Gravitation
- If \( r_1, v_1, L_1 \) and \( r_2, v_2, L_2 \) are radii, velocities, and angular momenta of a planet at perihelion and aphelion of its elliptical orbit around the Sun respectively, then
- KCET - 2025
- Physics
- Gravitation
- The gravitational potential energy of an object of mass 5 kg at a height of 10 m above the surface of the Earth is:
- MHT CET - 2025
- Physics
- Gravitation
- 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.
- MHT CET - 2025
- Physics
- Gravitation
- The gravitational potential energy of a 2 kg object at a height of 5 m above the surface of the Earth is?
- MHT CET - 2025
- Physics
- Gravitation
Questions Asked in NEET exam
- Two heaters A and B have power rating of 1 kW and 2 kW, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is :
- NEET (UG) - 2024
- work, energy and power
The following graph represents the T-V curves of an ideal gas ( where T is the temperature and V the volume) at three pressures P1, P2 and P3 compared with those of Charles's law represented as dotted lines.
Then the correct relation is :- NEET (UG) - 2024
- Ideal Gases
- In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is 100x (kcal m-2)yr-1, what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?
- NEET (UG) - 2024
- Ecosystems
- 1 gram of sodium hydroxide was treated with 25 ml. of 0.75 M HCI solution, the mass of sodium hydroxide left unreacted is equal to
- NEET (UG) - 2024
- Structural Representations Of Organic Compounds
In the given figure, which component has thin outer walls and highly thickened inner walls?
- NEET (UG) - 2024
- Cell Wall
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].