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August 21, 2017
Angular Velocity

Try this problem, useful for Physics Olympiad, based on the propeller's angular velocity. The Problem: An airplane propeller is rotating at (1900)rpm (rev/min). (a)Compute the propeller's angular velocity in rad/s. (b) How many seconds does it take for the propeller to run through (35^\circ)? Solution: An airplane propeller is rotating at (1900)rpm (rev/min). (1)rpm = […]

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August 20, 2017
TIFR 2013 problem 23 | Complete-Not Compact

Try this problem 23 from TIFR 2013 named - Complete not compact. Question: TIFR 2013 problem 23 True/False? Let \(X\) be complete metric space such that distance between any two points is less than 1. Then \(X\) is compact. Hint: What happens if you take discrete space? Discussion: Discrete metric space as we know it […]

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August 20, 2017
Total Charge of a Sphere

Try this problem, useful for the Physics Olympiad Problem based on total charge of a sphere. The Problem: Suppose a charge (Q) is distributed within a sphere of radius (R) in such a way that the charge density (\rho(r)) at a distance r from the centre of the sphere is $$ \rho(r)=K(R-r) \hspace{2mm }for\hspace{2mm} 0<r<R$$ […]

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August 18, 2017
Non-homeomorphic (TIFR 2013 Math Solution problem 22)

TIFR 2013 Math Solution Discussion Question: The sets \([0,1)\) and \((0,1)\) are homeomorphic. Hint: Check some topological invariant. TIFR 2013 Math Solution Also Visit: College Mathematics Program Discussion: In \([0,1)\), \(0\) seems to be a special point, as compared to \((0,1)\) where every point has equal importance (or non-importance). If \(f:X\to Y \) is a homeomorphism […]

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August 18, 2017
Total Charge of a Circular Wire

Try this problem, useful for Physics Olympiad based on Total Charge of a Circular Wire. The Problem: A circular wire of radius (a) has linear charge density $$\lambda=\lambda_0cos^2\theta$$ where (\theta) is the angle with respect to a fixed radius. Calculate the total charge. Solution: Charge on an element (dl=ad\theta) is $$ \lambda_0cos^2\theta.ad\theta$$ Total charge $$ […]

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August 17, 2017
A Bouncing Ball

Try this problem, useful for Physics Olympiad, based on a bouncing ball. The Problem: A ball is dropped from a height (h) above a horizontal concrete surface. The coefficient of restitution for the collision involved is (e). What is the time after which the ball stops bouncing? Discussion: The time required for the free fall […]

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August 16, 2017
TIFR 2013 problem 21 | No fixed point Homeomorphism

Try this problem from TIFR 2013 problem 21 based on no fixed homeomorphism. Question: TIFR 2013 problem 21 True/False? Every homeomorphism of the 2-sphere to itself has a fixed point. Hint: \(z= -z\) implies \(z=0\) Discussion: 2-sphere means \( S^2=\left \{(x,y,z)\in\mathbb{R}^3 | x^2+y^2+z^2=1 \right \} \). i.e, \( S^2=\left \{v\in\mathbb{R}^3 | ||v||=1 \right \} \). \(||.||\) […]

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August 15, 2017
Period of a Planet

Try this Problem, useful for Physics Olympiad, based on the period of a planet. The Problem: Suppose that the gravitational force varies inversely as the \(n^{th}\) power of the distance. Then, the period of a planet in circular orbit of radius \(R\) around the sun will be proportional to (A) \(R^{\frac{n+1}{2}}\) (B)\(R^{\frac{n-1}{2}}\) (C) \(R^n\) (D) […]

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August 14, 2017
TIFR 2013 problem 20 | Sequence limit~Fixed Point

Try this problem 20 from TIFR 2013 based on Sequence Limit - Fixed Point. This problem is an application of the Banach Fixed Point Theorem. Question: TIFR 2013 problem 20 True/False? Consider the function \(f(x)=ax+b\) with \(a,b\in\mathbb{R}\). Then the iteration \(x_{n+1}=f(x_n)\); \(n\ge0\) for a given \(x_0\) converges to \(\frac{b}{1-a}\) whenever \(0<a<1\). Hint: Banach Fixed Point […]

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August 13, 2017
Collision Between Two Balls

Try this problem, useful for Physics Olympiad based on Collision Between Two Balls. The Problem:  A ball A moving with a velocity 5m/s collides elastically with another identical ball at rest such that the velocity of the A makes an angle of \(30^\circ\) with the line joining the centres of the balls. Then, (A) speed […]

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