Describe a situation where you would want a large amount of friction

If you're feeling cold, and I'm sure you have done this, you usually create friction when you rub your hands together to create heat. Sorry if this is not what you're looking for and not that high level.

when you are driving on the roads, which are covered with snow, especially if it's below freezing then you need large amount of friction between road and tyres of your vehicle. second example is applying break suddenly to stop or avoid accident during driving

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.

wavelength divides in half and speed stays the same.