Changing acceleration and forces are part of the excitement of a roller coaster ride. According to Newton's second law, F = "m"a, every part of our body must be exposed to a force to accelerate. Since our bodies are not symmetric, the direction of the force matters, and must be accounted for by ride designers. An additional complication…

Circular motion changes the perception of up and down. For a skater, the need to lean in towards the centre of an arc constitutes an embodiment of centripetal acceleration. This paper presents a discussion between a physicist and a high-school science teacher without previous physics studies at university level. The discussions started as part of…

Students' understanding of forces in circular motion is often incomplete. The problems are not limited to confusions about centripetal acceleration and centrifugal forces. This paper considers possible effects of different interventions by a teacher who has discovered the many types of free-body diagrams drawn by students for circular motion in a…

Large drop towers let you experience a couple of seconds of nearly free fall before stopping gracefully in magnetic brakes or bouncing a number of times on compressed air, as in the Turbo Drop tower considered in this work, where many complementary representations are used. An accelerometer taken along on the ride captured the forces experienced…

Your body is not a point particle. The nature and direction of the forces counteracting gravity influence your experience of uniform rectilinear motion--as does your own orientation in relation to the force of gravity. Sensors in smartphones or other devices can capture these forces, and help establish a connection between the personal experience…

Students often use incoherent strategies in their problem solving involving force and motion, as revealed, e.g. when they are asked to draw force diagrams for amusement rides involving circular motion, whether in horizontal or vertical planes. Depending on the questions asked, assignments involving circular motion can reveal different types of…

Take a selection of balls and marbles along to a nearby playground slide and let students investigate factors that may influence how balls accelerate down an inclined plane. Students can make hypotheses in small groups, plan investigations to test multiple possible explanations and draw conclusions about the importance of different variables. The…

Free fall is commonly discussed as an example of the equivalence principle, in the context of a homogeneous gravitational field, which is a reasonable approximation for small test masses falling moderate distances. Newton's law of gravity provides a generalisation to larger distances, and also brings in an inhomogeneity in the gravitational field.…

Describing the motion in a vertical roller coaster loop requires a good understanding of Newton's laws, vectors and energy transformation. This paper describes how first-year students try to make sense of force and acceleration in this example of non-uniform circular motion, which was part of a written exam. In addition to an analysis of the exam…

An amusement park is full of examples that can be made into challenging problems for students, combining mathematical modelling with video analysis, as well as measurements in the rides. Traditional amusement ride related textbook problems include free-fall, circular motion, pendula and energy conservation in roller coasters, where the moving…

Vertical amusement rides let your body experience the tickling sensation of feeling light, but also feeling much heavier than as usual, due to velocity changes as you move up and down. Family rides offer different possibilities to visualize the forces that are experienced by your accelerating body. This paper presents a number of different ways to…

Trampolines can be found in many gardens and also in some playgrounds. They offer an easily accessible vertical motion that includes free fall. In this work, the motion on a trampoline is modelled by assuming a linear relation between force and deflection, giving harmonic oscillations for small amplitudes. An expression for the cycle-time is…

Friction is an important phenomenon in everyday life. All children are familiar with playground slides, which may thus be a good starting point for investigating friction. Motion on an inclined plane is a standard physics example. This paper presents an investigation of friction by a group of 11-year olds. How did they plan their investigations?…

Comparing two objects falling together is a small-scale version of Galileo's classical experiment, demonstrating the equivalence between gravitational and inertial mass. We present here investigations by a group of ten-year-olds, who used iPads to record the drops. The movie recordings were essential in the follow-up discussions, enabling the…

A roller coaster ride comes to an end. Magnets on the train induce eddy currents in the braking fins, giving a smooth rise in braking force as the remaining kinetic energy is absorbed by the brakes and converted to thermal energy. In this paper an IR camera was used to monitor the temperature of the first braking fin, before, during and after the…