enEnglishguગુજરાતી
JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
A \(70\, kg\) man leaps vertically into the air from a crouching position. To take the leap the man pushes the ground with a constant force \(F\) to raise himself The center of gravity rises by \(0.5\, m\) before he leaps. After the leap the \(c.g.\) rises by another \(1\, m\). The maximum power delivered by the muscles is : (Take \(g\, = 10\, ms^{-2}\))
- A \(6.26\times10^3\) Watts at the start
- B \(6.26\times10^3\) Watts at take off
- C \(6.26\times10^4\) Watts at the start
- D \(6.26\times10^4\) Watts at take off
Answer & Solution
Correct Answer
(B) \(6.26\times10^3\) Watts at take off
Step-by-step Solution
Detailed explanation
According to energy conservation , Let be take off speed \(v.\) So, \(\frac{1}{2}m{v^2} = mgh;\;\) \(Here\;h = 1\;m\) \(v = \sqrt {2g} \) Now Maxium power delivered by musheles is given by \(P\; = 2Fv = 2 \times mg \times \sqrt {2g} \)…
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
- A \(2\,meter\) long scale with least count of \(0.2\,cm\) is used to measure the locations of objects on an optical bench. While measuring the focal length of a convex lens, the object pin and the convex lens are placed at \(80\,cm\) mark and \(1\,m\) mark, respectively. The image of the object pin on the other side of lens coincides with image pin that is kept at \(180\,cm\) mark. The \(\%\) error in the estimation of focal length isJEE Mains 2023 Hard
- Sixty four rain drops of radius 1 mm each falling down with a terminal velocity of \(10 cm / s\) coalesce to form a bigger drop. The terminal velocity of bigger drop is _________ \(cm / s\).JEE Mains 2026 Hard
- Two bodies are projected from ground with same speeds \(40 ms ^{-1}\) at two different angles with respect to horizontal. The bodies were found to have same range. If one of the body was projected at an angle of \(60^{\circ}\), with horizontal then sum of the maximum heights, attained by the two projectiles, is \(.......m\). (Given \(g =10 ms ^{-2}\) )JEE Mains 2023 Medium
- Consider a Young’s double slit experiment as shown in figure. What should be the slit separation \(d\) in terms of wavelength \(\lambda \) such that the first minima occurs directly in front of the slit \((S_1)\)?
JEE Mains 2019 Hard - The radius of gyration of a uniform rod of length \(l,\) about an axis passing through a point \(\frac{l}{4}\) away from the centre of the rod, and perpendicular to it, isJEE Mains 2020 Medium
- The radius of third stationary orbit of electron for Bohr's atom is \(R\). The radius of fourth stationary orbit will be:JEE Mains 2024 Hard
More PYQs from JEE Mains
- Let \(a \in R\) and let \(\alpha, \beta\) be the roots of the equation \(x^2+60^{\frac{1}{4}} x+a=0\). If \(\alpha^4+\beta^4=-30\), then the product of all possible values of \(a\) is \(......\)JEE Mains 2023 Hard
- A \(12\,V\) battery connected to a coil of resistance \(6 \,\Omega\) through a switch, drives a constant current in the circuit. The switch is opened in \(1\,ms\). The emf induced across the coil is \(20 \;V\). The inductance of the coil is ........... \(mH\)JEE Mains 2023 Medium
- As shown below, bob \(A\) of a pendulum having massless string of length ' \(R\) ' is released from \(60^{\circ}\) to the vertical. It hits another bob \(B\) of half the mass that is at rest on a friction less table in the center. Assuming elastic collision, the magnitude of the velocity of bob A after the collision will be (take g as acceleration due to gravity.)
JEE Mains 2025 Hard - If \(S=\{z \in C:|z-i|=|z+i|=|z-1|\}\), then, \(n(S)\) is:JEE Mains 2024 Medium
- If \(\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}} \frac{96 x^2 \cos ^2 x}{\left(1+e^x\right)} \mathrm{d} x=\pi\left(\alpha \pi^2+\beta\right), \alpha, \beta \in \mathbb{Z}\), then \((\alpha+\beta)^2\) equalsJEE Mains 2025 Medium
- A solid sphere of radius \(r\) made of a soft material of bulk modulus \(K\) is surrounded by a liquid in a cylindrical container. A massless piston of area \(a\) floats on the surface of the liquid, covering entire crosssection of cylindrical container. When a mass \(m\) is placed on the surface of the piston to compress the liquid, the fractional decrement in the radius of the sphere, \(\left( {\frac{{dr}}{r}} \right)\) isJEE Mains 2018 Medium