Unformatted text preview: ring x: the displacement of the end of the spring. The magnitude of the force that one segment of a string exerts on an adjacent segment is called tension. Since strings can only pull, and not push, the direcWon of tensions are always away from the object the strings are agached to. T T In a rope dangling from a ceiling, tension is the greatest at the ceiling due to the weight of the rest of the rope dangling below. If the mass of the rope can be neglected, the tension is the same throughout the rope. Applying Newton's 2nd Law,
T ! T " = #ms a
For a rope with negligible mass, #ms = 0.
T = T"
The force exerted by the fricWonless massless pulley on the rope is always a normal force. A normal force has no component tangent to the rope, so it cannot produce a change in the magnitude of tension.
If the pulley axis is not acceleraWng, the net force on the pulley axis is zero. Right Pulley: The weight, W, is pulling the pulley axis down. Two tensions (of the same magnitude, W/2) a...
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