00405 - Physics

Learning outcomes

At the end of the course, the student is expected to know the fundamental principles of point & rigid body Mechanics, fluid Mechanics and Thermodynamics, in order to describe and interpret the physical phenomena pertaining to agriculture and the agro-forestry sector.

Course contents

MEASUREMENT AND UNITS OF MEASURE: physical quantities, symbols and units of measure; measuring instruments, systems of units of measure: SI system, c.g.s. system, fundamental and derived units.

VECTORS: vectors and scalars; vector algebra: sum, product of a scalar and a vector, scalar product, vector product; moment.

KINEMATICS: material point kinematics: position, displacement, mean and instantaneous velocity, mean and instantaneous acceleration; uniform rectilinear motion, uniform circular motion, uniformly accelerated motion.

DYNAMICS: concept of force; examples of forces: gravitational force, weight force, elastic force, frictional force. Newton’s Laws. Rigid body kinematics and centre of mass. First cardinal equation of dynamics. Second cardinal equation of dynamics in brief: case of a rigid body rotating about a fixed axis; moment of inertia (in brief). Cardinal equations of Statics. Mechanical work and potential energy; work-energy principle; kinetic energy; conservation law for mechanical energy. Examples: work done by the gravitational force and by an elastic force.

FLUID MECHANICS: Eulerian and Lagrangian description (in brief). Density and pressure. Fluid Statics: Pascal's law; Stevin’s law; Archimedes’ law. Fluid Dynamics: flow rate; continuity equation; Bernoulli’s equation.

THERMODYNAMICS: temperature and heat. The Laws of Thermodynamics. Specific heat. Examples of thermodynamic processes: adiabatic, isochoric, isobaric, isothermal, cyclic processes, free expansion. Entropy and its relevance; reversible and irreversible processes; the arrow of time. Ideal gas law. Heat engines; efficiency; Carnot cycle and efficiency of the Carnot heat engine.

EXERCISES: after each unit, exercises at different degrees of difficulty will be solved in class.

Readings/Bibliography

• Lecture notes
• Exercises uploaded on the course virtual space
• Mazzoldi P., Nigro M., Voci C., Elementi di Fisica - Meccanica e Termodinamica. EdiSES

Teaching methods

The course is divided into two parts:

• Theory classes: the main theoretical topics will be treated.
• Exercises: exercises will be solved in class to help the student familiarize with the theoretical aspects of the subject and to develop basic calculation and problem-solving skills.

Assessment methods

The final examination for Physics consists in a written test plus optional work to be carried out individually and handed in on the day the written test is taken.

The written test lasts 2 hours and consists of 8 questions: 3 short numerical exercises worth 3 points each; 3 open-ended theory questions worth 3 points each; 2 numerical exercises worth 6 points each.

The optional work consists of writing concept maps of all the theoretical topics covered in class. The concept maps must meet the following requirements:

(i) be complete, i.e. cover all the topics discussed in class

(ii) be drawn using at least two different colours

(iii) be handwritten on paper

(iv) bear the student's name, surname and badge number on each side.

Concept maps will be assessed during the written examination and can be worth up to 4 points. If the maps do not meet one or more of the above requirements, no marks will be given. A preliminary check of the fulfilment of the requirements is possible by arranging a meeting with the professor.

The final mark is the sum of the marks obtained in the written test and the mark eventually obtained for the concept maps. If the total score exceeds 30 points, the grade is 30 with honours.

Teaching tools

Laboratory tools and instruments will occasionally be brought in class.

Office hours

See the website of Mirko Maraldi

See the website of Sergio Lo Meo