# Problem: A 1.5 kg block and a 2.5 kg block are attached to opposite ends of a light rope. The rope hangs over a solid, frictionless pulley that is 30 cm in diameter and has a mass of 0.75 kg. When the blocks are released, what is the acceleration of the lighter block?

###### FREE Expert Solution

In this problem, we're going to consider Newton's second law of motion:

Newton's second law:

$\overline{){\mathbf{\Sigma }}{\mathbf{F}}{\mathbf{=}}{\mathbf{m}}{\mathbf{a}}}$

For a solid pulley, the moment of inertia:

$\overline{){\mathbf{I}}{\mathbf{=}}\frac{\mathbf{1}}{\mathbf{2}}{\mathbf{M}}{{\mathbf{R}}}^{{\mathbf{2}}}}$

Angular acceleration:

$\overline{){\mathbf{\alpha }}{\mathbf{=}}\frac{\mathbf{a}}{\mathbf{R}}}$

We let m1 = 1.5 kg

m2 = 2.5 kg.

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###### Problem Details

A 1.5 kg block and a 2.5 kg block are attached to opposite ends of a light rope. The rope hangs over a solid, frictionless pulley that is 30 cm in diameter and has a mass of 0.75 kg. When the blocks are released, what is the acceleration of the lighter block?

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Torque on Pulley Systems concept. If you need more Torque on Pulley Systems practice, you can also practice Torque on Pulley Systems practice problems.