inertia
Friction in the opposite direction to the direction of motion. Weight directly downwards. Reaction force directly upwards.
Gravity acts in the direction directly towards the centre of the Earth. Drag acts in the direction directly opposite the bird's movement.
Directly away from the source.
And it not only DOES; it works in no other way. Friction is a sneaky thing. You know how a thermos "knows" to keep the hot stuff hot and the cold stuff cold? Well, friction always knows in which direction you're trying to go and pushes against you!
south
inertia
inertia
DIRECTLY East.
Friction in the opposite direction to the direction of motion. Weight directly downwards. Reaction force directly upwards.
Directly opposite the center of the earth.
Gravity acts in the direction directly towards the centre of the Earth. Drag acts in the direction directly opposite the bird's movement.
west
Directly away from the source.
Minnesota is directly north of Iowa.
And it not only DOES; it works in no other way. Friction is a sneaky thing. You know how a thermos "knows" to keep the hot stuff hot and the cold stuff cold? Well, friction always knows in which direction you're trying to go and pushes against you!
a uniaxial force is a force applied only in one direction - directly in the axis direction
You put the sun directly behind you.