Push hard and fast (but not too fast)

Newton's second law is closely related to his first law of motion. It mathematically gives the cause-and-effect relationship between force and changes in motion. Newton's second law is quantitative and is used extensively to calculate what happens in situations involving a force. All external forces acting on a system add together to produce a net force Fnet. A larger net external force produces a larger acceleration. This acceleration is directly proportional to, and in the same direction as,...

An interesting force in everyday life is the force of drag on an object when it is moving in a fluid. Like friction, the drag force always opposes the motion of an object. Unlike simple friction, the drag force is proportional to some function of the velocity of the object in that fluid. This functionality is complicated and depends upon the shape of the object, its size, its velocity, and the fluid it is in. For most large objects, such as cyclists, cars, and baseballs, that are not moving too...

Force and momentum are intimately related. Force acting over time can change momentum, and Newton's second law of motion can be stated in its most broadly applicable form in terms of momentum. Momentum can be applied to systems where the mass is changing, such as rockets, as well as to systems of constant mass. Also, momentum continues to be a key concept in the study of atomic and subatomic particles in quantum mechanics. One can consider systems with varying mass in some detail; however, the...

A hydraulic jump is a sudden rise in fluid depth in open channels, occurring when high-velocity (supercritical) flow transitions to low-velocity (subcritical) flow. This phenomenon requires an upstream Froude number greater than 1, as flows with Fr1<1 remain subcritical, making a hydraulic jump impossible due to the need for negative head loss, which violates thermodynamic principles.The characteristics of a hydraulic jump depend on the upstream Froude number and are classified as...

Forces affect every moment of our life. Our bodies are held to the Earth by force, and they are held together by the forces of charged particles. When we open a door, walk down a street, lift a fork, or touch a baby's face, we are applying force. Our body's atoms are held together by electrical forces, and the core of an atom, called the nucleus, is held together by the strongest force known to us—nuclear force.
The study of motion is called kinematics, but kinematics only describes the way...

A square-threaded screw jack is a mechanical device widely used for lifting heavy loads or applying considerable force. Its operation is based on converting the force applied at its handle into a torsional moment, causing the upward impending motion of the screw. This movement is accomplished by overcoming the static friction between the threads of the screw and the jack.
To better comprehend how a screw jack functions, consider the completely unraveled thread as a block in contact with the...