COMEDK · Physics · 9. Gravitation
A body is projected vertically upwards from the surface of earth with a velocity 'v' to reach a height of 10R, where R is the radius of the earth, then v is
- A \(\sqrt{\dfrac{20gR}{11}}\)
- B \(\sqrt{\dfrac{10gR}{11}}\)
- C \(\sqrt{\dfrac{21gR}{11}}\)
- D \(\sqrt{\dfrac{21gR}{10}}\)
Answer & Solution
Correct Answer
(A) \(\sqrt{\dfrac{20gR}{11}}\)
Step-by-step Solution
Detailed explanation
By conservation of mechanical energy: \(K_i + U_i = K_f + U_f\) \(\dfrac{1}{2}mv^2 - \dfrac{GMm}{R} = 0 - \dfrac{GMm}{R + 10R}\) \(\dfrac{1}{2}mv^2 = \dfrac{GMm}{R} - \dfrac{GMm}{11R}\) \(\dfrac{1}{2}v^2 = \dfrac{10GM}{11R}\) \(v^2 = \dfrac{20GM}{11R}\) Using…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- The centre of mass of a system of two bodies of masses \(M\) and \(m,(M>m)\), separated by a distance \(d\) isCOMEDK 2014 Easy
- Across the 220 V source of internal resistance \(20 \Omega\), how many lamps of \(40 \mathrm{~W}, 100 \mathrm{~V}\) can be connected in parallel so that all the lamps may glow with full brightness.COMEDK 2025 Medium
- A particle of mass 3 g and charge \(60 \mu \mathrm{C}\) is released from rest in a uniform electric field of intensity \(10^5 N C^{-1}\). If the value of kinetic energy attained by the particle after moving through a distance of 2 cm is \(m \times 10^{-2} \mathrm{~J}\), then the value of m is:COMEDK 2025 Medium
-
In the figure shown above, a cell of negligible internal resistance and emf 22 V is connected to a network of resistors. If the power dissipated in the whole circuit is \(\dfrac{x}{10 R}\), then the value of \(x\) is:COMEDK 2025 Medium - The space between the two plates of a parallel plate capacitor is fully filled with a conducting slab. Then the capacitance of the capacitor is :COMEDK 2025 Easy
- The photoelectric current of voltage in a certain experiment is \(1.5 \mathrm{~V}\). What is the maximum kinetic energy of photoelectrons emitted?COMEDK 2015 Easy
More PYQs from COMEDK
- Electromagnets are made of soft iron because soft iron hasCOMEDK 2014 Easy
- The shortest wavelengths of Paschen, Lymen and Balmer series are in the ratioCOMEDK 2024 Medium
- If \(2,7,9,5\) are subtracted respectively from four numbers forming a \(\mathrm{GP}\), the resulting numbers are in \(\mathrm{AP}\), then the smallest of the four numbers isCOMEDK 2017 Easy
- For the reaction, \(\mathrm{A}+3 \mathrm{~B} \rightarrow 2 \mathrm{C}+\mathrm{D}\), the concentration of \(\mathrm{A}\) changes from 0.0150 to 0.0125 in 1 minute. The rate of formation of \(\mathrm{C}\) in \(\mathrm{mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\) is:COMEDK 2024 Medium
- The feasible region represented by the constraints:
\(x + 2y \leq 120\);
\(x + y \geq 60\);
\(x - 2y \geq 0\);
\(x \geq 0\) and \(y \geq 0\)COMEDK 2026 Easy - The photographic industry relies on the special light sensitive properties ofCOMEDK 2014 Easy