# Book

Pages: 3 (513 words) Published: April 7, 2013
German University in Cairo Faculty of EMS Department: Mechatronics Prof. Dr. Imam Morgan

Mechanics II (ENME 402) Assignment (2)

Name ID Group

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-1-

Problem (1) A tractor-trailer is traveling at 90 km/h when the driver applies his brakes. Knowing that the braking forces of the tractor and the trailer are 16 kN and 60 kN, respectively, determine: (a) the distance traveled by the tractor-trailer before it comes to a stop, (b) the horizontal component of the force in the hitch between the tractor and the trailer while they are slowing down.

-2-

Problem (2) The system shown is initially at rest. Neglecting the masses of the pulleys and the effect of friction in the pulleys, determine: (a) the acceleration of each block, (b) the tension in each cable.

-3-

Problem (3) The motion of an oscillating flywheel is defined by the relation:    0 e7 t / 6 sin 4 t,

where θ is expressed in radians and t in seconds. Knowing that θo= 0.4 rad, determine, the angular coordinate, the angular velocity, and the angular acceleration of the flywheel when; (a) t = 0.125 s, (b) t = ∞.

-4-

Problem (4) When the power to an electric motor is turned on the motor reaches its rated speed of 2400 rpm in 4 s, and when the power is turned off the motor coasts to rest in 40 s. Assuming uniformly accelerated motion, determine the number of revolutions that the motor executes: (a) in reaching its rated speed, (b) in coasting to rest.

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Problem (5) The rectangular block shown rotates about the diagonal OA with a constant angular velocity of 6.76 rad/s. Knowing that the rotation is counterclockwise as viewed from A, determine the velocity and acceleration of point B at the instant shown.

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Problem (6) The bent rod ABCD rotates about a line joining points A and E with a constant angular velocity of 12 rad/s. Knowing that the rotation is clockwise as viewed from E, determine the velocity and...