#### Newton’s 2nd law/ demonstration track with Cobra4

Principle According to Newton’s 2nd law of motion for a mass point, the relationship between mass, acceleration and force are investigated. Tasks The distance-time law, the velocity time law and the relationship between mass, acceleration and force are determined. The conservation of energy can be investigated. Benefits Accurate results due to measurements with low friction: […]

#### Surface tension of liquids

PrincipleThe cohesive forces in a liquid generate tension on its surface, the so-called surface tension. A metal ring that is plunged into a liquid is withdrawn from the liquid. At a certain tensile force, the liquid film will be disrupted from the ring. Based on the tensile force and ring diameter, the surface tension of […]

#### Surface tension with the ring method (Du Nouy method)

Principle The force is measured on a ring shortly before a liquid film tears using a torsion meter. The surface tension is calculated from the diameter of the ring and the tear-off force. Benefits High sensitivity measurement possible thanks to ring method Analogue set-up that can also be used as a demo experiment in the lecture […]

#### Viscosity measurement with the falling ball viscometer

Principle Due to internal friction among their particles, liquids and gases have different viscosities. The viscosity, a function of the substance’s structure and its temperature, can be experimentally determined, for example, by measuring the rate of fall of a ball in a tube filled with the liquid to be investigated. Benefits Viscosity measurement for two […]

#### Viscosity of Newtonian and non-Newtonian liquids (rotary viscometer)

PrincipleThe viscosity of liquids can be determined with a rotation viscometer, in which a motor with variable rotation speed drives a cylinder immersed in the liquid to be investigated with a spiral spring. The viscosity of the liquid generates a moment of rotation at the cylinder which can be measured with the aid of the […]

#### Density of liquids

Principle The density of water and glycerol is determined as a function of temperature using the Mohr balance. Benefits Mohr density balance enables high-precision measurements Interdisciplinary use also in applied sciences or physical chemistry Tasks The density of water and glycerol is measured in 1 to 2 °C steps over a temperature range from 0 […]

#### Mechanical conservation of energy/ Maxwell’s wheel

Principle A disc, which can unroll with its axis on two cords, moves in the gravitational field. Potential energy, energy of translation and energy of rotation are converted into one another and are determined as a function of time. Benefits High and sturdy set-up Expressive demonstration of energy conversion Convert potential energy in energy of […]

#### Flow Measurement / Ultrasonic Doppler effect

Principle The aim of this experiment is to study the relationship between the ultrasonic Doppler effect and the flow velocity or the Doppler angle. Benefits Ideal for teaching the basics of the Doppler effect in fluids Experiment setup can be upgraded to perform experiments like flow mechanics and Doppler sonography Compact, easy to understand experiment […]

#### Mechanics of flow

Principle The ultrasonic Doppler effect is used for studying the laws of steadily and laminarly flowing liquids in a tube circuit, which form the basis of numerous technical applications. The experiment focuses particularly on the relationship between the flow velocity and the cross-sectional tube area (continuity condition) as well as on the relationship between the […]

#### Surface of rotating liquids

Principle A vessel containing liquid is rotated about an axis. The liquid surface forms a paraboloid of rotation, the parameters of which will be determined as a function of the angular velocity. Benefits Didactical unique Interdisciplinary use also in applied sciences or physical chemistry Tasks On the rotating liquid surface, the following are determined: the […]

#### Reversible pendulum

Principle By means of a reversible pendulum, terrestrial gravitational acceleration g may be determined from the period of oscillation of a physical pendulum, knowing neither the mass nor the moment of inertia of the latter. Benefits Quick and easy set-up Determine the gravitational constant g immediately without knowledge of mass or moment of inertia Automatically […]

#### Determination of the gravitational constant/ computerised Cavendish balance

Principle Two small lead spheres are positioned on a beam, which is freely suspended on a thin metal wire. At the beginning the large lead spheres are positioned symmetrically opposite to the small spheres in that way that the attractive forces are eliminated. There after, the large spheres are swung so that they are close […]

#### Moments of inertia and torsional vibrations

Principle Various bodies perform torsional vibrations about axes through their centres of gravity. The vibration period is measured and the moment of inertia determined from this. Benefits Selection of materials allows demonstrating all aspects of moments of inertia in one experiment Clear and easy set-up Tasks The following will be determined: The angular restoring moment […]

#### Hooke’s law

PrincipleThe validity of Hooke’s law is determined for two helical springs with different spring constants. The elongation of the helical spring, which depends on the deforming force, is studied by means of the weights of masses. For comparison, a rubber band, for which no proportionality exists between the exerted force and the resulting elongation, is […]

#### Mechanical hysteresis

Principle The relationship between torque and angle of rotation is determined when metal bars are twisted. The hysteresis curve is recorded. Benefits Beyond Hooke’s law Hysteresis – mostly known from the field of magnetism – can be experienced in mechanics Learn the meaning of the words stress, relaxation and equilibrium in a physics context Various […]

#### Modulus of elasticity / Youngs Modulus

Principle A flat bar is supported at two points. It is bent by the action of a force acting at its centre. The modulus of elasticity is determined from the bending and the geometric data of the bar. Benefits Find out the parameters that give a bar stability Measure the difference of elasticity in various […]

#### Moments

Principle Coplanar forces (weight, spring balance) act on the moments disc on either side of the pivot. In equilibrium, the moments are determined as a function of the magnitude and direction of the forces and of the reference point. Benefits Understand the relation and the difference between moments and force. Smart designed equipment that makes […]

#### Moments of inertia of different bodies/ Steiner’s theorem with Cobra4

Principle The moment of inertia of a solid body depends on its mass distribution and the axis of rotation. Steiner’s theorem elucidates this relationship. Benefits Angular oscillation apparaturs includes five different body shapes for in-depth experimenting High-precision movement sensor Very robust and durable setup Tasks The moments of inertia of different bodies are determined by […]

#### Laws of gyroscopes/ cardanic gyroscope

Principle If the axis of rotation of the force-free gyroscope is displaced slightly, a nutation is produced. The relationship between precession frequency or nutation frequency and gyro-frequency is examined for different moments of inertia. Additional weights are applied to a gyroscope mounted on gimbals, so causing a precession. Benefits Unique set-up of the Magnus-type gyroscope […]

#### Mechanical conservation of energy/ Maxwell’s wheel with measure Dynamics

Principle A wheel, which can unroll around its axis on two cords, moves a gravitational field. This process is filmed with a video camera. The potential energy, kinetic energy, and rotational energy are converted into one another and determined as a function of time with the aid of the “measure Dynamics” software. Benefits High and […]

#### Laws of gyroscopes/ 3-axis gyroscope

Principle The momentum of inertia of the gyroscope is investigated by measuring the angular acceleration caused by torques of different known values. In this experiment, two of the axes of the gyroscope are fixed. The relationship between the precession frequency and the gyro-frequency of the gyroscope with 3 free axes is examined for torques of […]

#### Centrifugal force

Principle A body with variable mass moves on a circular path with adjustable radius and variable angular velocity. The centrifugal force of the body will be measured as a function of these parameters. Benefits Easy to read measures Several loadable weights enable variable set-up Freely set various steady rotational velocities Tasks Determination of the centrifugal […]

#### Moment of inertia and angular acceleration with a precision pivot bearing

Principle A moment acts on a body which can be rotated about a bearing without friction. The moment of inertia is determined from the angular acceleration. Benefits Long runtime Nearly friction-less movement due to precision bearing and precision pulley Steady set-up prevents interferences Tasks From the angular acceleration, the moment of inertia is determined as […]

#### Moment of inertia and angular acceleration with Cobra4 and a precision pivot bearing

Principle If a constant torque is applied to a body that rotates without friction around a fixed axis, the changing angle of rotation increases proportionally to the square of the time and the angular velocity proportional to the time. Benefits Long runtime Nearly friction-less movement due to precision bearing Steady set-up prevents interferences Data logging […]

#### Laws of collision/ demonstration track with a 4-4 timer

Principle The volocities of two gliders, moving without friction on a demonstration track, are measured before and after collision, for both elastic and inelastic collision. Tasks Elastic collision The impulses of the two gliders as well as their sum after the collision. For comparison the mean value of the impulses of the first glider is […]

#### Ballistic pendulum

Principle A classic method of determining the velocity of a projectile is to shoot it into a resting mass hung as a pendulum. The projectile remains in the pendulum and swings with it. This is an inelastic collision in which the momentum remains unchanged. The velocity of the pendulum’s mass (including the projectile’s mass) at […]

#### Projectile motion with measure Dynamics

Principle A steel sphere is launched by a ballistic unit and the resulting trajectory is filmed with the aid of a video camera. The “measure Dynamics” software is used to demonstrate the dependence of the trajectory on the launching angle and on the initial velocity, and to determine the range and height of the trajectory. In […]

#### Projectile motion

Principle A steel ball is fired by a spring at different velocities and at different angles to the horizontal. The relationships between the range, the height of projection, the angle of inclination and the firing velocity are determined. Benefits Learn a classic method to determine a projectile’s velocity See how to utilize conservation laws for […]

#### Free fall with measure Dynamics

Principle The aim of this experiment is to film a high-speed video of a sphere falling from the height of fall h. The “measure Dynamics” software is used for the graphical representation of the distance as a function of time t and also as a function of the square of time t^2 as well as the graphical representation of […]

#### Free Fall with timer 2-1

PrincipleA sphere falls freely over certain distances. The falling time is measured and evaluated from diagrams. The acceleration due to gravity can be determined. Benefits Gravitation scrutinized Find out how the velocity of a falling object increases Didactical demonstration of the falling distances Visualise the squared distance-time law Steady set-up All crucial parts directly engineered […]

#### Free fall with Cobra4

Principle The fall times t are measured for different heights of fall h. h is represented as the function of t or t², so the distance-time law of the free fall results as h = 1/2 · g · t². Then the measured values are taken to determine the acceleration due to gravity g. Benefits […]

#### Newton’s 2nd law/ demonstration track with measure Dynamics

Principle A mass, which is connected to a cart via a silk thread, drops to the floor. The resulting motion of the cart will be recorded by way of a video camera and evaluated with the “measure Dynamics” software. The relationship between distance and time, velocity and time, and the relationship between mass, acceleration, and force […]

#### Newton’s 2nd law/ demonstration track

Principle The distance-time law, the velocity time law, and the relationship between mass, acceleration and force are determined with the aid of the demonstration track rail for uniformly accelerated motion in a straight line. Tasks Determination of: Distance travelled as a function of time Velocity as a function of time Acceleration as a function of […]

#### Basic measurement techniques

Principle Caliper gauges, micrometers and spherometers are used for the accurate measurement of lengths, thicknesses, diameters and curvatures. Measuring procedures, accuracy of measurement and reading accuracy are demonstrated. Benefits Foundation of every practical sciences lab course Aquire the skills to measure basic mechanical variables Realise the limits of measuring accuracy Combine different measurements to determine […]