If Keiji stands on a hill with a strong wind coming from his back, and he is wearing a loose-fitting t-shirt, in which direction will the t-shirt most likely billow, and why? Make your response very short.
Keiji's t-shirt will billow forwards, away from his body. The reason for this is that the wind provides a force from behind Keiji that pushes against the fabric of the t-shirt. Since the t-shirt is loose-fitting, the force of the wind can get underneath the fabric and cause it to move away from Keiji's body towards the direction the wind is blowing, which is forwards from his perspective.