# two bodies are travelling with equal acceleration

two bodies are travelling with equal acceleration in the same direction and are in contact with each other. What will the force exerted by 1st body on second be?

By taking an example of masses 5 and 10 kg and acceleration of $2ms^{-2}$, I get force = 10N. How can I derive a general form?

@Asheshanand Acharya

I know force will change. See here : Two bodies A and B are accelerating together towards right. What should me the force exerted by A on B? If we take 5 and 10 as masses, and 2 as acceleration, we get forces equal to 20N and 10N. Therefore force on B by A = 20-10=10N I am asking how can I derive a formula for any variable mass $m_A$ and $m_B$? Thank you!

## 1 Answer

The answer depends on what Force (F) is causing them to move with the acceleration 2m/(s.s).
If the F is due to gravity(or anything like that, example electrostatic force) the force applied by one other will be zero. As is evident from two falling objects, even if they are in contact they do not apply force on each other.
If the F is on body of mass 5kg, draw free body diagram of 10kg to get the answer of 20N.
If the F is on body of mass 10kg, draw free body diagram of 5kg to get the answer of 10N.