![<b><u>Answer</u></b>](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6v21ic7hkn3093etn5ivm9mdxd58w43jt5.png)
The magnitude of the acceleration to the nearest hundredth is
![3.39ms^(-2)](https://img.qammunity.org/2020/formulas/physics/middle-school/3ey2qak6xoqucp34bhg6soaydpb4w7n6hj.png)
![<b><u>Explanation</u></b>](https://img.qammunity.org/2020/formulas/physics/middle-school/tqa1xcmpoluaj05886dwnjufofg3blb4fn.png)
We have to analyze the external forces acting on the two solid blocks.
The tension,
![T](https://img.qammunity.org/2020/formulas/mathematics/middle-school/6x2ybduif4g01w55ss3jxxawbb3dgqm80e.png)
in the string, the weight
![w_1=12.4g](https://img.qammunity.org/2020/formulas/physics/middle-school/b7xa6477w16uhmmyljzzcm0h9234xztlv9.png)
and
![w_2=25.5g](https://img.qammunity.org/2020/formulas/physics/middle-school/6l9mnhpqqhci4m5kl9g09fbz7cvct7xwwo.png)
are all illustrated in the diagram in the attachment.
Recall from Newton's law of motion that,
![F=ma](https://img.qammunity.org/2020/formulas/physics/middle-school/hoqv0uuwk5hamoxytydy5e8slsjemaiqzz.png)
, where
![m](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cq4we7rbaw8mvm9yuf211b2ffjo45x6v6x.png)
is mass measured in kilograms and
![a](https://img.qammunity.org/2020/formulas/mathematics/high-school/p8wjdflgvtvya4hppwbx9xwxr8jb2zdxwx.png)
is the acceleration in
![ms^(-2)](https://img.qammunity.org/2020/formulas/physics/middle-school/6h0tl4chodb3txo6ekyt90c5oewv7d66vx.png)
.
For the
![12.4kg](https://img.qammunity.org/2020/formulas/physics/middle-school/rxgkwth186i3edhc8uhd6n2nx0w336guj6.png)
mass the resultant upward force is
![T-12.4g](https://img.qammunity.org/2020/formulas/physics/middle-school/kft2gdowqe4avcy6p9muk82zknxwkwstdi.png)
.
Applying
![F=ma](https://img.qammunity.org/2020/formulas/physics/middle-school/hoqv0uuwk5hamoxytydy5e8slsjemaiqzz.png)
to the
![12.4kg](https://img.qammunity.org/2020/formulas/physics/middle-school/rxgkwth186i3edhc8uhd6n2nx0w336guj6.png)
mass gives
![T-12.4g=12.4a...eqn(1)](https://img.qammunity.org/2020/formulas/physics/middle-school/sgdpl307flbbgcm44qawjds29x9lzd1vdq.png)
.
For the
![25.5kg](https://img.qammunity.org/2020/formulas/physics/middle-school/ehywwshy14rwg1buspp4a3bwezq82cf6r0.png)
mass the resultant downward force is
![25.5g-T](https://img.qammunity.org/2020/formulas/physics/middle-school/vagor6ujl0f32coquei5u7ypyrq7nlixh1.png)
Applying
![F=ma](https://img.qammunity.org/2020/formulas/physics/middle-school/hoqv0uuwk5hamoxytydy5e8slsjemaiqzz.png)
to the
![25.5kg](https://img.qammunity.org/2020/formulas/physics/middle-school/ehywwshy14rwg1buspp4a3bwezq82cf6r0.png)
mass gives,
![25.5g-T=25.5a...eqn(2)](https://img.qammunity.org/2020/formulas/physics/middle-school/f0aa7coa1rpbqvayuyr7ciz4rqwvei5sgq.png)
Adding the two equations gives us,
![25.5g-12.4g=25.5a+12.4a](https://img.qammunity.org/2020/formulas/physics/middle-school/1ru2d1ltpxkmsp0zxue8yak11yyqvwsjyb.png)
This simplifies to
![13.1g=37.9a](https://img.qammunity.org/2020/formulas/physics/middle-school/b7l3jnxhldt1o0e7576fxpz6ng82hchb98.png)
We divide both sides by
![37.9](https://img.qammunity.org/2020/formulas/physics/middle-school/mcda0h3stcdxqms0fhe1mw7hwhqayu3tia.png)
to obtain,
![(13.1g)/(37.9)=a](https://img.qammunity.org/2020/formulas/physics/middle-school/5kxnkae9vikgicgv3z6rj8zgqtos4qxwk0.png)
We were given
![g=9.8ms^(-2)](https://img.qammunity.org/2020/formulas/physics/middle-school/nz1td7lzdp0ljlplbo3qkartvsevbmw2os.png)
We substitute this value to obtain,
![a=(13.1)/(37.9) * 9.8](https://img.qammunity.org/2020/formulas/physics/middle-school/o2uq8mo5r7o4lp8sfq309ksay0sgzfjl68.png)
![a=3.3873 \ms^(-2)](https://img.qammunity.org/2020/formulas/physics/middle-school/ygb6v0ohmel3iimk4olpjfh68w7xe8b99y.png)
Hence the magnitude of the acceleration to the nearest hundredth is
![3.39ms^(-2)](https://img.qammunity.org/2020/formulas/physics/middle-school/3ey2qak6xoqucp34bhg6soaydpb4w7n6hj.png)