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

SPECIFIC PREREQUISITES FOR THE COURSE:

To better understand the topics covered in this course, students shall have already acquired knowledge of basic algebra, basic mathematics (solution of first-order equations and of systems of two equations in two unknowns) and basic trigonometry.

COURSE CONTENTS:

• Measurements 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.

• 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.

• 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.

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

Readings/Bibliography

The teaching materials for this course (lecture notes and suggested exercises) are available on the Virtuale Learning Environment (https://virtuale.unibo.it/?lang=en ).

Further readings:

• 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. It is not allowed to exit the classroom during the test.

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. The results of the written examination will be published within 10 working days. A final grade of 18 or higher is required to pass. If the total score exceeds 30 points, the grade is 30 with honours.

Mid-course examinations. It is possible to replace the complete written test with two separate partial examinations. The first will take place approximately halfway through the course, while the second will be held on the first available examination date after classes have ended. No additional dates will be offered for these examinations.

With reference to the Course Contents section above, the first partial examination covers: measurements and units of measure; vectors; kinematics; dynamics.

With reference to the Course Contents section above, the second partial examination covers: thermodynamics; fluid mechanics. Concept maps, if prepared, must be submitted on the day of the second examination.

Each examination has a duration of 1.5 hours and consists of 5 questions: 2 short numerical exercises, 2 open-ended theory questions, and 1 numerical problem. The mark for each examination is awarded on a scale of 30.

Only students who receive a mark of at least 14/30 in the first partial examination may take the second. Students who do not receive a mark of at least 14/30 in the first partial examination must take the complete written examination during one of the available examination sessions. Students who do not take the second partial examination on the first available date will automatically forfeit the mark obtained in the first partial examination.

The written examination is fulfilled if a mark of at least 14/30 is also obtained in the second partial examination. In this case, the final mark for the written component is the average of the marks obtained in the two partial examinations, plus any points awarded for the concept maps. The examination is passed with a final mark of at least 18/30. If the overall score exceeds 30 points, the final mark is 30/30 with honours.

 

Students with learning disorders and/or temporary or permanent disabilities: please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students ) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

Teaching tools

Laboratory tools and instruments will occasionally be brought in class.

In case of difficulties in understanding part of the course content, the instructor is available for clarification meetings, which shall be scheduled via email.

Office hours

See the website of Mirko Maraldi

See the website of Sergio Lo Meo