Why forces are measured in newtons

It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. I wanted to know about the experiments that Newton performed which led to the formulation of laws of motion.

In particular I am interested in the following:. How did he measure the forces in order to discover that the net force was directly proportional to the acceleration produced? My teacher told me that he probably used springs but doesn't that require assuming Hooke's Law to be true. If this was the case how did Hooke measure forces before formulating his law.

Newton did not measure forces for this purpose, nor could he, the second law itself is needed to make sense of measuring forces. What is actually measured are velocities and accelerations, or rather times and distances traveled, so any "measuring" of force has to presuppose at some point that the law holds establishing the Hooke's law would have to presuppose it too, see Did Hooke's law come from experiments, or was it mathematically derived from Newtonian mechanics?

What Newton measured were the effects it predicted for collisions, pendulums, circular motion, etc. For impulsive forces in collisions its action was instantaneous, and so imparted finite momentum in zero time. This is the notion that appears in Newton's early works. But the reason was helped, in this case, by the prior work of Galileo on the falling bodies and inertia, Descartes and Huygens on collisions, and Huygens on circular motion, which discredited the Aristotelian "internal forces".

It is this quantity that I mean hereafter everywhere under the name of body or mass. And the same is known by the weight of each body; for it is proportional to the weight, as I have found by experiments on pendulums, very accurately made, which shall be shewn hereafter. I tried the thing in gold, silver, lead, glass, sand, common salt, wood, water, and wheat Please use it for calculation of load value, etc.

Force is usually measured by applying it to a calibrated measuring instrument which resists the force and indicates or records its magnitude. A force gauge is a small measuring instrument used across all industries to measure the force. Force is a vector quantity, with both direction and magnitude. The SI unit of force is the newton N ; defined as the unit of force which would give to a mass of one kilogram an acceleration of 1 meter per second squared.

There are a lot of force types including tension, compression, shearing, bending, and friction. Torque is a measure of how much a force acting on an object causes that object to rotate. The distance r is from the pivot point to the point where the force acts. Imagine pushing a door to open it. BUT as we have said earlier Newtons are used to measure Force, and since Weight is a downward force caused by Gravity, weight is measured in Newtons. It should also be remembered that the Mass of an object is constant whereas the weight of an object can change in Gravity, and this will be affected by where the object is in relation to other objects.

For instance, your weight on the Moon would be approximately one sixth of your weight on earth due to the effect of Gravity. If we wish to find out the speed of an object and we know the distance travelled and the time taken we can use the following formula:. Testing your understanding. Force: What is force? Measuring forces. Describing Forces. What does a force do? What is friction? Assessment Questions. Vectors and Scalars: What is a vector quantity? Examples of Vectors.

What is a Scalar Quantity? Examples of Scalars. Test your understanding of vectors and scalars. Examples for each law are given..

Work, Energy and Power: Definitions for work, energy and power.