Question #78ee5

Aug 3, 2017

See below.

Explanation:

The static friction force is given by ${\mu}_{s} {m}_{1} g$ and the applied force is ${m}_{2} g$

Now

${m}_{2} g - {\mu}_{s} {m}_{1} g = \left({m}_{2} - {\mu}_{s} {m}_{1}\right) g = \left(12 - 0.43 \cdot 45\right) g = - 7.35 g$

so block 1 remains stopped, because the tension induced by block 2 (${m}_{2} g$) is less than the static friction force ${\mu}_{s} {m}_{1} g$