A solid sphere whose diameter is 3.5 ft weighs 600 lb. The mass moment of inertia of the sphere with respect to a horizontal line through its center of gravity is A. 22.8 slug-fr’. B. 28.5 slug-ff. C. 36.0 slug-ft 2 . D. 45.6 slug-ft 2 .
A solid wheel is being rolled toward the right along a horizontal surface by a force whose line of action is horizontal. The diameter of the wheel is 2.5 ft, the wheel weighs 80 lb, and the magnitude of the force is 15 lb. If the friction force is sufficient to prevent slipping of the wheel on the supporting surface, the magnitude of the linear acceleration of the center of gravity would be A. 3.22 fps per sec. C. 5.15 fps per sec. B. 4.03 fps per sec. D. 6.44 fps per sec.
As indicated in Examination Figure 5, a solid cylindrical disk is caused to rotate about a stationary axis, which passes through the center of gravity of the disk. The force that produces rotation is applied to the rim of the disk by means of a cable, which is wound around the disk and is attached to a body. The radius of the disk is 2.5 ft, the weight of the disk is 800 lb, and the weight of the body is 300 lb. When the body is supported in the position shown, the body and the disk are at rest. If the support tor the body is taken away, the disk will rotate without friction while the body moves downward under the action of its weight. The angular velocity of the disk after the body has moved 5 tt from the position shown would be A. 3. 70 rad per sec. C. 5.70 rad per sec. B. 4.70 rad per sec. D. 6.70 rad per sec.
Blocks 1 and 2 in Examination Figure 6 are connected by a cable, which passes over a sheave. Block 1 slides along a horizontal surface under the action of a horizontal force applied by the cable when block 2 is permitted to fall vertically through the air. Block 1 weighs 120 lb, block 2 weighs 50 lb, the coefficient of friction for the materials of block 1 and the supporting surface is 0.3, and friction in the sheave can be neglected. At the instant at which the blocks were in the positions shown, the magnitude of the velocity of each block was 5 fps. After block 2 has moved 3 ft downward from the position shown, the magnitude of the velocity of each block would be A. 6.40 fps. C. 7.04 fps. B. 6.75 fps. D. 7.30 fps.
The diameter of a solid wheel is 3.5 ft, and its weight is 60 lb. The wheel is rolled toward the left along a horizontal surface under the action of a horizontal force whose magnitude is 20 lb. If the friction force is sufficient to prevent slipping, what is the magnitude of the linear acceleration of the center of gravity of the wheel? A.. 3.21 fps per sec B. 5.32 tps per sec C. 7.16 fps per sec D. 8.15 fps per sec