Читать книгу Fundamentals of Heat Engines - Jamil Ghojel - Страница 64

1 1.1 Determine the velocity required to keep satellite P in orbit at altitude S km above the surface of the earth. Force F2 is the balancing force that keeps the satellite in circular orbit. The gravitational force acting on the satellite, treated as a particle, is

2 1.2 A crank‐slider has a crank radius R = 100 mm, a connecting rod length L = 200 mm, and a crank angular speed ω = 100 rpm counterclockwise.Write the expressions for the displacement x and velocity of piston PDetermine the velocity when θ = 450.

3 1.3 Determine the moment of inertia and radius of gyration about an axis through the centre of a composite body with a central inner disk of mass 4 kg and radius 300 mm and a ring of mass 5 kg and radius 400 mm. The masses of the four spokes shown can be ignored.

4 1.4 A constant torque of 150 Nm applied to a turbine rotor is sufficient to overcome the constant bearing friction torque and give it a speed of 75 rpm from rest after 9 revolutions. When the 150 Nm torque is removed, the turbine rotor turns for a further 23 revolutions before stopping. Determine the moment of inertia of the rotor and the bearing friction torque.

5 1.5 A motor is required to reach an operating speed of 500 rpm in a time of 30 seconds from rest at a constant acceleration. DetermineThe required constant accelerationThe number of revolutions the motor turns to reach this operating speed. The motor is then turned off and comes to rest under a constant deceleration of 0.1 rad/s2 due to bearing friction. How long and how many revolutions does it take for the motor to come to reset?