PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
The lid of a jar of preserves has a radius of 3.5cm. To unscrew the lid requires a couple of 15Nm.
(a) If the lid is to be opened by hand, calculate the minimum force that must be applied to each side of the lid for it to turn.
(b) A kitchen gadget with 15cm-long handles can clamp onto the lid. Calculate the minimum force that must be applied to each of the gadget's handles to unscrew the lid.
(c) Suggest why consumers are happy to buy such a gadget rather than just use their hands.