Hookes Law, set of 5 springs with different spring constants, forces required for 1cm extension are 0.25N, 0.5N, 1N, 1.5N, and 2.5N respectively, Pre-stress has been removed for accurate results, With a hook to support a weight hanger and a red arrow to indicate position
PineCAR Racer Basic Car Kit (scouting car), includes wood block, wheels, hubcaps, two lead-free one-piece axles and four lead-free nail-type axles. Wheels and axles should be the same on all cars in a race. Block dimensions - 1 3/4in w x 7in l (4.44 cm x 17.7 cm)