4 kg Lesson Objective: RF=ma with pulleys The block in the diagram below is on a smooth table and is being pulled by a force of 8N to the right and by a force of 5N to the left. What is the acceleration of the block?

Lesson Objective: RF=ma with pulleys The block in the diagram below is on a smooth table and is being pulled by a force of 8N to the right and by a force of 5N to the left. What is the acceleration of the block? 4 kg How does this situation compare this problem: 4 kg 0.5 kg 0.8 kg The block in the diagram below rests on a smooth table and is attached by light inextensible strings to two particles of mass 0.5kg and 0.8kg that free to hang over the edge of the table due to smooth pulleys. What is the acceleration of the block?

Pulleys If two particles are connected by a string passing over a smooth pulley or peg, the heavier particle will move downwards and the lighter one upwards. Three modelling assumptions are important here (and often appear in examination questions). * As before, if they are connected by an inextensible string, they will have the same acceleration. * If the pulley or peg is smooth, the tension in the portions of string either side of the pulley or peg will be the same. Anyone who has made a guitar from an empty shoe box and an elastic band is relying on the friction between box and band to keep one part of the band more taut than the other. * If the string is light, it has no mass, and therefore the tension will be constant along its length. If the string had mass, the portion of the string higher up would be more tense as it would have more mass to support beneath it.

Two blocks are connected by a light inextensible string which passes over a smooth pulley. They both start 1m from the floor. Find the acceleration in the system and the time it takes for the 8kg block to hit the floor. 5kg 8kg

Two particles P and Q of masses 6 kg and 3 kg respectively are connected by a light inextensible string. Particle P rests on a rough horizontal table. The string passes over a smooth pulley fixed at the edge of the table, and Q hangs vertically. If the Friction force is 2gN and the system is released from rest. Find in terms of g : a) the acceleration of Q, b) the tension in the string, c) the force exerted on the pulley by the string.

Two particles of masses 2 kg and 7 kg are connected by a light inelastic string passing over a fixed pulley. The system is released from rest with both portions of the string vertical, and both particles at a height of 3m above the ground. In the subsequent motion, the 7 kg mass hits the ground. Find the greatest height reached by the 2 kg mass if the pulley is of such height that the mass never reaches the pulley. 2kg 7kg HARDER

I think i did this a better way using the result from part i