gravity
potential energyGravity.
Air resistance
No. At least not by the force that's perpendicular to the motion. When you push a baby stroller (or a car), you do work, but the force of gravity, downward and perpendicular to the motion, doesn't.
The resultant force on a falling toy is downward. It is the weight of the toy minus any air resistance, which for short distances is negligible.
well the motion is round and round but the force that stops it falling over is centrifugal force :)
potential energyGravity.
downward motion
Air resistance
motion of free falling object does not have friction, while motion of the cart has force of friction
No. At least not by the force that's perpendicular to the motion. When you push a baby stroller (or a car), you do work, but the force of gravity, downward and perpendicular to the motion, doesn't.
The resultant force on a falling toy is downward. It is the weight of the toy minus any air resistance, which for short distances is negligible.
well the motion is round and round but the force that stops it falling over is centrifugal force :)
terminal velocity
Ten newtons downward, by definition.
As you walk down the stairs, you apply a force to keep yourself from falling down the stairs. The force is in the upward direction, but your movement is in the downward direction. If the force is in the opposite direction of motion, work done by the force is negative. Gravitational force, because it pulls down, does positive work.
gravity
The equation of motion is not modified. Net force = mass x acceleration, whether freely falling or not.