Which is not an example of a lever? light switch scissors knife broom

Let's first remember what a lever is used for... it allows one to magnify the amount of force being applied to something, via a stiff arm. Now let's go through a process of elimination.

Light switch: Yes there's a stiff arm. And although you're not doing much work turning a light on and off, the switch does magnify the force you apply to the mechanism hidden behind the wallplate. We'll call it a lever.

Knife: Acting as a wedge to force two halves a whole apart. However, it can be used as a lever too. Pushing a knife onto something doesn't always cut it right away. Sometimes, you have to put the point down and then apply force to the handle, using whatever you're cutting as fulcrum. Ultimately a wedge, but still acting as a lever.

Broom: Are you on your knees sweeping with a toothbrush, which takes a lot of work, or are you holding a broom handle in two hands, moving one and using the other as a fulcrum? Thought so. Still a lever.

Scissors: Like the knife, they act as a wedge, cutting through thin materials. However, the cutting point is right at the fulcrum of the scissors! You're not magnifying any force there. So I would say no, scissors are not an example of a lever.

Explanation:

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach