# mechanics Q16

• Nov 6th 2012, 08:56 AM
abdulrehmanshah
mechanics Q16
Attachment 25567 can anyone q.16 only the part where we have to prove that x is greater than or equal to
• Nov 6th 2012, 10:32 AM
skeeter
Re: mechanics Q16
for masses A & B to accelerate ...

$\displaystyle T > 2mg\sin{\theta}$

$\displaystyle mg > T$

using these two inequalities, you should be able reach the first conclusion in the problem statement.

for the second conclusion, start with net force equations for each mass ...

$\displaystyle T - 2mg\sin{\theta} = 2ma$

$\displaystyle mg - T = ma$

---------------------------- combine ...

$\displaystyle mg - 2mg\sin{\theta} = 3ma$

solve for acceleration ...

$\displaystyle a = \frac{g(1-2\sin{\theta})}{3}$

... remember that this acceleration is only applicable for a displacement of magnitude x for both masses.

now, you finish it.
• Nov 6th 2012, 08:52 PM
abdulrehmanshah
Re: mechanics Q16
oh man i told u just the last part i solved this all but couldnt solve last part