Question

Three bolocks are connected(mass_1 on the left connected to mass_2 with a string which is T_1. Mass_2 is connected to Mass_3 with a string, T_2. the force is holding on to T_3 which is connected to mass_3) and pulled to the right on a horizontal frictionless table by a force witha magnitude of T_3=65N. If m_1= 12 kg, m_2 =24 kg and m_3= 31 kg, what is a) acceleration of the sysem and b) tensions T_1 AND C) T_2 in the inerconnecting cords.

what is the formula I would use to find a? Is it a= F/m? for the tensions how would I find them?

I assume you are ignoring friction. If so, then acceleration=force/total mass.

Now, the tensions on each cord or spring pulling some masses is given by

tension=massespulled*acceleration.

The masses pulled is the mass being pulled. For instance, The string pulling mass1 and mass2 is

Tension=(M2+M1)*acceleration.