WBJEE · Physics · Rotational Motion
The velocity of a car travelling on a straight road is \(3.6 \mathrm{kmh}^{-1}\) at an instant of time. Now travelling with uniform acceleration for \(10 \mathrm{s}\), the velocity becomes exactly double. If the wheel radius of the car is \(25 \mathrm{cm}\), then which of the following is the closest to the number of revolutions that the wheel makes during this 10 s?
- A 84
- B 95
- C 126
- D 135
Answer & Solution
Correct Answer
(B) 95
Step-by-step Solution
Detailed explanation
We have, \(\theta=2 \pi n=\frac{\left(\frac{v_{f}^{2}}{r^{2}}-\frac{v_{1}^{2}}{r^{2}}\right)}{\left(2 \frac{a}{r}\right)}\) \[ n=\frac{v_{f}^{2}-v_{i}^{2}}{(2 a r)(2 \pi)}=95 \]
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 de-Broglie wavelength of an electron (mass \(=1 \times 10^{-30} \mathrm{kg},\) charge \(\left.=16 \times 10^{-19} \mathrm{C}\right)\) with a kinetic energy of \(200 \mathrm{eV}\) is (Planck's constant \(=6.6 \times 10^{-34} \mathrm{Js}\)WBJEE 2013 Medium
- One \(\mathrm{Kg}\) of copper is drawn into a wire of \(1 \mathrm{~mm}\) diameter and a wire of \(2 \mathrm{~mm}\) diameter. The resistance of the two wires will be in the ratioWBJEE 2009 Medium
- \(n\) identical droplets are charged to \(v\) volt each. If they coalesce to form a single drop, then its potential will beWBJEE 2010 Hard
- Find the equivalent capacitance between \(A\) and \(B\) of the following arrangement :
WBJEE 2022 Easy - What is the phase difference between two simple harmonic motions represented by \(x_{1}=A \sin \left(\omega t+\frac{\pi}{6}\right)\) and \(x_{2}=A \cos (\omega t) ?\)WBJEE 2012 Easy
- A small metal sphere of radius \(a\) is falling with a velocity \(v\) through a vertical column of a viscous liquid. If the coefficient of viscosity of the liquid is \(\eta\), then the sphere encounters an opposing force ofWBJEE 2014 Easy
More PYQs from WBJEE
- If \(\log _7 2=\lambda\), then the value of \(\log _{49}(28)\) isWBJEE 2011 Easy
- If \(\mathrm{I}=\lim _{\mathrm{x} \rightarrow 0} \sin \left(\frac{\mathrm{e}^{\mathrm{x}}-\mathrm{x}-1-\frac{\mathrm{x}^{2}}{2}}{\mathrm{x}^{2}}\right)\), then limitWBJEE 2021 Easy
- A variable circle passes through the fixed point \(A(p, q)\) and touches \(X\) -axis. The locus of the other end of the diameter through \(A\) isWBJEE 2019 Hard
- The co-ordinates of the focus of the parabola described parametrically by \(x=5 t^2+2, y=10 t+4\) areWBJEE 2009 Hard
- The reaction that takes place when \(\mathrm{Cl}_2\) gas is passed through conc. \(\mathrm{NaOH}\) solution is :WBJEE 2009 Hard
- \(A\) heating element of resistance \(r\) is fitted inside an adiabatic cylinder which carries a frictionless piston of mass \(m\) and cross section A as shown in diagram. The cylinder contains one mole diatomic current the element temperatures time \(t\) as (a and \(\beta\) are constants), while pressure remains constant. The atmospheric pressure above the piston is \(P_{0}\). ThenWBJEE 2014 Hard