Well, what's going to be the downward force of gravity here?

那么 这里向下的重力是多少呢？

By exerting a force downward, an equal and opposite force pushes upward, and the object accelerates.

通过施加一个向下的力，将会产生一个同等的并且反向的向上的推动力，这个推动力促使物体加速运动。

That force of buoyancy pushes up on each ring, until it matches the downward force of gravity.

浮力在每个环上向上推，直到它与向下的重力平衡。

There is going to be the downward force of gravity on both of these blocks of ice.

向下的重力向下的重力等于。

At first, it may make sense to explain gravity like this, gravity is a downward force created by the earth.

首先，这样解释重力是有意义的，重力是由地球产生的向下的力。

That's because the upward buoyant force is always stronger than the downward force of gravity.

那是因为向上的浮力总是强于向下的重力。

Once it overcomes the downward force of gravity, the plane takes off.

一旦它克服了向下的重力，飞机就会起飞。

All you need is a powerful enough upward force to counteract the downward force of gravity.

您所需要的只是一个足够强大的向上力来抵消向下的重力。

The team found that the insects pushed off with a downward force that exceeded the surface tension. That's the force that glues the water surface molecules together.

他们发现这种昆虫使用大于表面张力的下向力来推动自己，这种力能让水面分子聚合在一起。

These connections are designed to  take the massive forces of the engine, both the forward thrust force and the  downward force of the engine's weight.

这些连接旨在承受发动机的巨大作用力，包括向前的推力和发动机重量的向下力。

And just like the spinning top pointing against the downward force of gravity to stay vertical, the spinning football wants to push against the main force acting against it.

就像旋转的陀螺与向下的重力相反以保持垂直一样，旋转的橄榄球想要推动作用于它的主要力量。

And, again because pressure increases  with depth, the upward force acting on the bottom side is larger than the downward force acting  on the top side.

而且，由于压力随着深度的增加而增加，作用在底部的向上的力大于作用在顶部的向下的力。

Teeter-totters, salad tongs, and bottle openers are all levers, meaning that a downward force exerted on one end can be transferred and increased in an upward direction at the other end, allowing a small force to lift a heavy weight.

跷跷板、沙拉钳和开瓶器都是杠杆，这表明在一端施加的向下的力，可以在另一端向上转移并增加，从而用很小的力就能举起重物。