What is the mass of the Milky Way?

We can consider the Sun to be a satellite of the Milky Way. The Sun revolves around the center of the Milky Way with a radius of 8 kpc. The period of revolution is 230 million years. What is the mass of the Milky Way?
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A motion of a Conical Pendulum


A ball is attached to a string and swung so that it travels in a horizontal circle.

Suddenly the angular velocity is increased. Will the angle with the vertical increase, decrease or stay the same? Justify your answer.

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A ball is attached to a string and swung so that it travels in a horizontal circle

ballstringswung.jpgA ball of mass 0.2 kg is attached to a massless string 1 m long and swung so that it travels in a horizontal circle of radius 0.5 m.

a) Draw a free-body diagram.
b) Find the force of tension in the string as the ball swings in a horizontal circle.
c) Find the period of the ball’s motion.

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A car moves around a curved banked road


A curved road is banked at an angle β, and there is no friction between the road and the car’s tires. The road has a radius of curvature of 50 m.
A car has a speed of 90 km/h.

Find angle β.

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The car passes over the top of a convex bridge


A car has a mass of 1500 kg and travels with a speed of 5 m/s. The car passes over the top of a convex bridge that has a radius of curvature equal to 10 m. What is the force of the bridge on the car as it passes over the top?

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To determine the acceleration due to gravity by means of a conical pendulum

ExpConPenA student conducted an experiment to measure the acceleration of gravity. He used a conical pendulum. The conical pendulum is a string with a bob (weight) that revolves around an axis through its point of suspension.
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A block and a triangular wedge move together

Problem20_2A block of mass m and a triangular wedge of mass M move together without slipping due to a pulling force F. The triangular wedge has a slope α. There is no friction between any pair of surfaces. Derive an equation of pulling force.

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