# Ropes and Pulleys.

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Ropes and Pulleys

Pulleys Pulleys only change the direction of the tension force not the magnitude

All three 50 kg blocks are at rest
All three 50 kg blocks are at rest. Is the tension in rope 2 greater than, less than or equal to the tension in rope 1? greater than less than equal to STT8.4

All three 50 kg blocks are at rest
All three 50 kg blocks are at rest. Is the tension in rope 2 greater than, less than or equal to the tension in rope 1? greater than less than equal to Newton’s first law for the block on the left proves that the tension equals the weight. Newton’s first law for either of the individual blocks on the right proves that the tension equals the weight for an individual. STT8.4

The block on the far right is moving up with constant speed
The block on the far right is moving up with constant speed. Is the tension in rope 2 greater than, less than or equal to the tension in rope 1? greater than less than equal to STT8.4

The block on the far right is moving up with constant speed
The block on the far right is moving up with constant speed. Is the tension in rope 2 greater than, less than or equal to the tension in rope 1? greater than less than equal to STT8.4 This is still a Newton’s first law situation!

In the figure to the right is the tension in the string greater than,
less than, or equal to the weight of block B? Greater than Less than Equal to STT8.5

In the figure to the right is the tension in the string greater than,
less than, or equal to the weight of block B? Greater than Less than Equal to STT8.5 This is a Newton’s second law situation for each of the blocks. Block A will accelerate to the right and block B will accelerate down. The net force on B must be down by Newton’s second law. The tension force exerted by the rope on block B must be less than the weight force exerted by the earth on block B.

Determine the reading on the spring scale
Complete 1-6

Acceleration constraints
Complete 1-5

Ropes and Pulleys (3)

Ropes and Pulleys (3)

Ropes and Pulleys (3)

Ropes and Pulleys Mathematical Approach

A mass, m1 = 3.00kg, is resting on a frictionless horizontal table is connected to a cable that passes over a pulley and then is fastened to a hanging mass, m2 = 11.0 kg as shown below. Find the acceleration of each mass and the tension in the cable.

Problem #1 A mass, m1 = 3.00kg, is resting on a frictionless horizontal table is connected to a cable that passes over a pulley and then is fastened to a hanging mass, m2 = 11.0 kg as shown below. Find the acceleration of each mass and the tension in the cable.