Abstract. Snap discs made of bimetal have many technical applications as thermostats. Jumping discs are a toy version of such snap discs. Besides giving technical information, we describe physical investigations. We show especially how, through simple measurements and calculations, you can determine the initial speed (~3.5 m s⁻¹), the acceleration (~30 000 m s⁻²) and the lower and upper snap temperature (~31; ~99 °C). High speed videos give even deeper insight into the jump.

Print publication: Issue 6 (November 2009)
Received 27 June 2009, in final form 10 August 2009