The dynamometer is a device that allows to measure forces, especially the so-called force-weight. By means of this instrument it is possible to calculate the force with which an object is attracted to the earth or, in other words, the weight of such object.
Basic idea of its operation
Inside the dynamometer there is a cylinder and inside it there is a stem with a graduated scale. At the end of the apparatus there is a hook where the object to be weighed is hung. Once the object is hung, the stem stops at a certain position and the value of the mark indicates the exact force that the object exerts.
If an object with a certain force is lowered into the water, the resulting force will be less. This does not imply that the object weighs less in the water, but rather that the weight of the object has been compensated by a different force, the pushing force exerted by the water on the object (in this case the dynamometer will mark the difference between the force- weight of the object and the force of the water).
Hooke's law and the concept of force
The dynamometer operation is based on the so-called Hooke's law. According to this law, the elongation of a material with a certain elasticity is directly related to the force applied to it.
Hooke's law served as the physical principle for the later invention of the dynamometer. Its inventor was the great English scientist Isaac Newton. It is worth remembering that the concept of force is measured precisely in newtons.
The idea of force refers to the possibility of an object accelerating. The acceleration of an object is a different matter than its speed. Thus, speed determines the speed of an object and is measured in units of distance per unit of time (such as meters per second or kilometers per hour). Instead, acceleration is the variation of change in velocity with time and is measured in units of velocity per unit of time. Consequently, anything that causes an object to accelerate, brake, or change direction is a force.
A device widely used by mechanics
Dynamometer measurements are applicable to motor vehicles, motorcycles, and all types of transportation. This tool is used to measure the power and force of the motors.
If the dynamometer incorporates additional sensors it is possible to measure other factors, such as fuel mixture, ambient temperature or engine temperature. All these measurements make it possible to diagnose the condition of the vehicles.
Photos: Fotolia - 9kwan / Rassco
