I'm now confused: If i take off a remote control helicopter at traffic lights while stationary, as I pull forward the car will travel around it and the helicopter will end up shattering the back window right? And it would be the same if i did it at 50mph, correct? Theoretically, my body is performing the same action as the helicopter if i jump on the bus, because I'm using energy to travel directly upwards as well. So why do I not travel? Is it because the helicopter can use it's energy whilst in the air to maintain the same position, whereas I fall back to the ground?