net force
US /nɛt fɔrs/
・UK /net fɔ:s/
B1 中級
n.名詞淨力
The net force acting on the object is zero, so it remains at rest.
影片字幕
月球的軌道超詭異！ (The Moon's Orbit is WEIRD)
- That means the net force on the moon is always towards the sun, and that's why the moon's trajectory never curves outwards towards the earth.
這意味著月球所受的淨力始終朝向太陽，這也是月球的軌跡從未向地球外側彎曲的原因。
- There's never a net force that would pull it that way.
從來沒有一種淨力量會把它拉向那邊。
大部分的碰撞其實是「一維」的！？ (Most Collisions Are Secretly in One Dimension)
- Most of the time, collisions in 2D or 3D result in a net force between the objects which is only in one direction—typically perpendicular to the surface where the objects collide, though if the surface is complicated or there's friction, it might be a different direction.
大多數時候，二維或三維的碰撞會在物體之間產生一個淨力，而這個淨力只朝一個方向——通常垂直於物體碰撞的表面，儘管如果表面很複雜或有摩擦力，方向可能會不同。
- Most of the time, collisions in 2D or 3D result in a net force between the objects which is only in one direction—typically perpendicular to the surface where the objects collide, though if the surface is complicated or there's friction, it might be a different direction.
大多數時候，二維或三維的碰撞會在物體之間產生一個淨力，而這個淨力只朝一個方向——通常垂直於物體碰撞的表面，儘管如果表面很複雜或有摩擦力，方向可能會不同。
飛機是怎麼飛的？ How Do Airplanes Fly?
- Airplanes stay in the air because of one simple fact: there is no net force on them.
飛機之所以可以在天上飛是因為一個簡單的事實: 沒有淨力
- And with no net force, an object at rest stays at rest, and an object in motion stays that way.
沒有淨力，靜止的物體就會保持靜止，動作中的物體就會保持它的動作