This question has been troubling me for quite some time.....?

If the butterfly is at the back of the bus, and the bus suddenly accelerates, yes, it may go splat as you put if so graphically. If is somewhere in the middle, it may sense the motion of the air (the air moves along with the bus) and adjust its own speed to more or less hover around its earlier spot.

Inertia is the factor just as a person gets pushed back into the seat and gets pushed against the front seat in the event of sudden acceleration and breaking respectively. The insects in front of the bus have very little time to react and do go splat over the windshield.

Its the same thing as people walking on to the bus then the bus starts moving . the people move with bus. So to the butterfly even suspended in the mid air will be pulled along. Because the air in the bus is also being pulled along. The butterfly is riding on the air that is riding in the bus.

Now if the bus accelerates to an impossible speed then the butterfly would stay stationary and the back of the bus will crash in to the butterfly.

Initially, the butterfly will tend to move slightly backwards due to inertia. However, everything inside the bus is part of the mass of the bus and therefore as the bus picks up speed, it will also move at the same speed as the bus. Therefore it will not go splat on the back of the bus.

damn good question..i think if the butterfly isnt attached to anything when the bus starts moving then it will hit the back of the bus..but then again if it is grounded somewhere on the bus when it starts moving can it then fly around freely???...wow...now i wanna get on a bus with a butterfly jus to do it...

because of the property of inertiaor the first law of motion,the mean position of butterfly will move towards the back of the bus.just as a standing man will have the tendency to fall backward.

There is no exact event for to solve this troubling.