Physics Answers

A particle of mass m is attracted to a force center with the force of magnitude k/ r². Use plane polar coordinates and find Hamilton's equations of motion.

A 5mm diameter string has original lenght of 2.2m. The string is pulled by a force of 220N. If the length of the string is 2.22m, calculate the stress, strain, and young's modulus of the string

The elastic limit of sgeel is 5.0Pa , find the maximum diameter of steel wire that can support a 700N weight without exceeding its elasgic limit.

Mass of 90 kg is supported by two strings with a=55 degrees and B= 40 degrees. Claculate the tension in the strings.

An earth satellite has a speed of 28070 km/hr when it is at its perigee of 220 km above Earth's surface. Find the apogee distance its speed at apogee, and its period of revolution.

A 60N block is resting at the top of a 30 degree slope of height 2m. It is attached to a thin walled cyliindrical pulley of mass 5 kg and radius 30 cm by a massless string that unwinds as the block slides downhill. If the acceleration of the block is 2.5 rad/second square, what is the value of the coefficient of kinetic friction? What is the velocity at the bottom of the slope?

A particle moves under the influence of a central force given by F(r) = - k/ rⁿ. If the particle's orbit is circular and passes through the force center, show that n = 5.

A 64 kg painter is standing 2.25 m distance up a ladder that is 3.0m long. If the ladder makes an angle of 69degrees with the ground, what torque does the painter's weight exert on the ladder?

A tire of radius 1.5 ft rolls without slipping along a horizontal track with uniform angular acceleration of 3 rad/s^2 from rest.

(a) How long will it take the point on tire touching the track to acquire an angular frequency of 30 rad/s and how far horizontally could the tire travel at this instant?

(b) What was the tangential speed, centripetal acceleration, and tangential acceleration of the point on tire in part (a)?

A propeller with three blades of mass 12 kg each , length of 1.25m each are 120 degrees relative to each other. If a torque N.m acts on this, what is the moment of inertia of the propeller? How long will it take to reach an angular velocity of 2000rad/s starting from rest?