Two blocks with masses 4.0kg and 8.0 kg are connected by a string and slide down a 30 degree inclined plane. The coefficient of kinetic friction between the 4.0 kg block and the plane is 0.25; that between the 8.0 kg block and the plane is 0.35(adsbygoogle = window.adsbygoogle || []).push({});

a) calculate the acceleration of each block

This part is easy i got it right, don't even need anyone to check it... 4 kg = 2.775 , 8 kg =1.4750

used for both blocks : mgx-ff=ma

b) calculate the tension in the string

I said since the bottom block accelerates faster it will create a tension which means both blocks will be connected by a rigid string with a tension in it... so this means i could solve them as a system ... this is where i need someone to verify i did it right or if not correct me....

i said that

(mgx1+mgx2)-(ff1+ff2) = (m1+m2)a

They are connected so they will have a new a in common for both which comes out to 1.9 .

So now i can find the tension by using either box and the first equations trying to find their acceleration alone... instead now i have

(for the bottom box)

mgx-ff-T=m(1.9)

So i get T = 3.5N

if i use this t in a newtons second law equation for the top one ill get 1.9 acceleration for it as well...

Can anyone let me know if i did any mistakes please? Thank you :) I really appreciate it

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# Homework Help: 2 blocks sliding down a incline connected by string (check please)

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