Recent content by venkatg

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    Undergrad Last geometry challenge (very difficult)

    Wickedprodigy - you probably have misunderstood the problem. The grass covers the entire circle; not just the boundary.
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    Finding work done by force of friction

    -fric = - 50 J (approximately) so "fric" is 50 J. right ;-)?
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    Moment of Inertia of a grinding wheel

    I think the time interval is not right. Probably the time intervals are not cumulative.
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    Calculating Friction & Coefficient: 0.50 kg Block on 30° Ramp

    Horizontal component of weight is mgsin(30) = 0.5mg normal component = mgcos(30) = sqrt(3) * mg/2 0.5mg - F = ma So F = 0.5mg - ma, we found F Also F = mu * sqrt(3) * mg/2 mu = F/(sqrt(3) * mg/2)
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    Find Out My Mistake: Comparing 2 Approaches to Find Spring Extension

    Yes, you cannot use energy conservation to get equilibrium position. The reason is simple. Imagine yourself positioning the mass hung from a spring. While you working to position the mass gently, you are applying external forces to make it settle down. So unless you account for these forces, the...
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    Calculate Arrow Speed & Height | Spring Energy Problem Homework

    The "average" force is F, so the energy is F * 1.3 or F = 192 = K* X /2 not K * X So the velocity is 28.85 * sqrt(2) = 40.8m/sec
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    Force in relation to angular momentum

    Yes, KE would increase when moved from 80cm to 20cm. It would increase 16 times! The KE is gained at the expense of work done overcoming the radial inertial force (m * w^2 * r) along a distance 60 cms. w = angular velocity. As the dumbell is moving from 80 to 20, the angular velocity...
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    Finding work done by force of friction

    You know the initial KE of the block at "A". You also know the kinetic energy of the block at "B". The reduction in the potential energy (m*g* 5 * sin(37)) must cause in increase in KE of the block. The frictional force will dissipate the KE of the block and the component of the applied force...
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    Determining Friction of Table with 100g, 75cm, 2s

    Normal force Fn is the reaction force due to the mass M and "g". (weight of the cart) The friction force is proportional to the Normal force, the constant of proportionality is the "mu". The applied force has to overcome BOTH the frictional force + inertial forces (M+m)*a
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    Bullet strikes block on friction surface

    We do not know if the collision is elastic or inelastic. You must use the momentum conservation. I worked out and found initial velocity of the bullet to be 460m/sec. I put this in the K.E equation and found the missing energy of 1614 J that was spent by the bullet in tearing the block
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    Statics ladder and friction less wall question

    oh yes, the anwer is tan(15)/2
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    Will an Airplane Maintain Uniform Circular Motion While Banking?

    Assume bank angle is theta. Assume lift force is L normal to the wings after banking Balancing vertical forces of flight: Lcos(theta) = mg Balancing horizontal forces, Lsine(theta) = mv^2/r Now tan(theta) = v^2/rg For a given theta and small r, v has to be small
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    Will an Airplane Maintain Uniform Circular Motion While Banking?

    It depends on what is radius of the circle needed and speed of the airplane. Sharper turns are better done at low speeds because the centripetal force is lower. At low speeds, list is developed by extending flaps and slats. since for a give radius of turn, the centripetal force is much lower...
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    Statics ladder and friction less wall question

    Well, the angle measured from the ground is 75, the actual result must be tan(90-75) = tan15
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    Statics ladder and friction less wall question

    Hint: Only the ground can provide a vertical reaction force and not the wall (no friction assumption). The ladder slips if the horizontal component of the force exceeds the frictional force. Frictional force = mu * vertical reaction (m*g as all load is borne by it) The compression...