instantaneous force meaning in English

瞬时力

He explained that gravity was not an instantaneous force as newton assumed , but that it took time to travel
他解释，重力不像牛顿说的那样是瞬时传播的，它的传播需要时间。
If the magnitude of the instantaneous agitating forces on a certain bed particle exceeds the stabilizing forces on the particle , the particle will begin to jump , roll , or slide along the bed until it becomes deposited downstream at a location where the magnitude of the instantaneous forces is smaller than the stabilizing forces
如果瞬间的搅动力幅度作用于某一河床粒子超过此粒子的稳定力时，此粒子会跳跃，旋转，或沿河床滑动直至积存于下游某处那里的瞬间搅动力幅度是小于其稳定力。