Rotating ball on a string, string is drawn up shortening the length

This problem has caused alot of dificulty. Both the ta and prof. have as yet not come up with a solution. A general concensus is that the higher circular path of the shortened length has a smaller diameter, unlike the picture. The answers are given as: A) L1^3 * sin^3 theta1 * tan theta1 = L2^3 * sin^3 theta2 * tan theta2 ...continues

spring supporting 2 blocks no friction

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block sliding with out friction in a rotating arm

please see attached

rotating bar with collar and cord

Please see attachment.What is the most straight forward way to solve, please provide explanations for major steps. Thanks Ans. are A)r accel = 72 m/sec^2 B) 1.25 N

Boxes going down belt to incline, velocity?

ans. is given as 4.36 m/sec. please include basic explanations Thanks

Roller coaster , find normal force from track

Ans. is given as 731 N Please include basic explanations thanks

Block going up an incline via wt. and pulley

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Rocket problem

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Need help finding the angle and magnitude

In an assembly operation, a robot moves an object first straight upwards and then to the east, around an arc forming on quarter of a circle of radius 4.80 that lies in an east-west vertical plane. The robot then moves the object upward and to the north, through a quarter of a circle of radius 3.70 cm that lies in a north south ...continues

free fall of a ball

see attachment