# Thread: Physics problem involving force

1. ## Physics problem involving force

I attached some pictures I quickly made in order to aid my explanation.

What is the acceleration of the system if someone acts upon the system where the blue arrow is? What about the tensional force between the 3 blocks?
physicssystem1.jpg

How can I calculate the compressional force if someone acts on the system where the blue arrow is? What about the tensional force?
physicssystem2.jpg

2. Originally Posted by colerelm1
I attached some pictures I quickly made in order to aid my explanation.

What is the acceleration of the system if someone acts upon the system where the blue arrow is? What about the tensional force between the 3 blocks?
physicssystem1.jpg
assuming no friction ...

$\displaystyle a = \frac{F}{m_1+m_2+m_3}$

each block will have the same acceleration.

set up a force equation for each block individually. for example ...

tension, $T_1$ , in the last string is the net force on $m_1$ ...

$\displaystyle T_1 = m_1 a = m_1 \cdot \frac{F}{m_1+m_2+m_3}$

3. same drill for the second problem ... acceleration of all three blocks will be

$\displaystyle a = \frac{F}{m_1 + m_2 + m_3}$

find the net force on each individual block and use Newton's 2nd law to determine the contact force and tension.

4. Originally Posted by skeeter
assuming no friction ...

$\displaystyle a = \frac{F}{m_1+m_2+m_3}$

each block will have the same acceleration.
What if I wanted to find the acceleration for each individual block?
set up a force equation for each block individually. for example ...

tension, $T_1$ , in the last string is the net force on $m_1$ ...

$\displaystyle T_1 = m_1 a = m_1 \cdot \frac{F}{m_1+m_2+m_3}$ Does this tension equation refer to the far left string when you say "in the last string"?

What if I wanted to find the acceleration of each block separately in the 2nd problem too?

5. Originally Posted by colerelm1
What if I wanted to find the acceleration of each block separately in the 2nd problem too?
set up a force diagram for each individual block then use Newton's 2nd law to set up a system of three equations ... solve for each force.