Раскадровка и хлопушка лежат на съёмочной площадке.

Because the subject is made of two things joined by и: раскадровка и хлопушка.

In Russian, when two nouns are connected by и and together form the subject, the verb is normally plural:

• раскадровка лежит = the storyboard is lying
• хлопушка лежит = the clapperboard is lying
• раскадровка и хлопушка лежат = the storyboard and the clapperboard are lying

So лежат is the 3rd person plural form of лежать.

In Russian, the verb to be is usually omitted in the present tense.

So English:

• The storyboard and the clapperboard are on the set

often becomes Russian:

• Раскадровка и хлопушка на съёмочной площадке

If you add лежат, the sentence becomes more specific: it tells you they are not just there, but that they are lying there.

So:

• ...на съёмочной площадке = ...on the set
• ...лежат на съёмочной площадке = ...are lying on the set / are lying there on the set

They are in the nominative case because they are the subject of the sentence.

You can tell from their dictionary-like forms:

• раскадровка
• хлопушка

These are the basic singular nominative forms of the nouns.

Because after на when it means on / at a location, Russian usually uses the prepositional case.

The noun площадка becomes:

• nominative: площадка
• prepositional: площадке

And the adjective must agree with it:

• nominative: съёмочная
• prepositional: съёмочной

So:

• на съёмочной площадке = on the film set / at the shooting location

This is a very common pattern:

• на столе = on the table
• на улице = in the street / outside
• на площадке = on the site / on the set

Лежать literally means to lie or to be lying. It is used for things that are in a horizontal position or are placed somewhere as objects.

So this sentence gives a visual image: the storyboard and the clapperboard are lying there on the set.

Compare:

• быть = to be
  Usually omitted in the present tense.
• находиться = to be located
  More formal or neutral.
• лежать = to lie, be lying
  More concrete and physical.

So these are slightly different in feel:

• Раскадровка и хлопушка на съёмочной площадке.
  They are on the set.
• Раскадровка и хлопушка находятся на съёмочной площадке.
  They are located on the set.
• Раскадровка и хлопушка лежат на съёмочной площадке.
  They are lying on the set.

Usually лежат is the more natural choice if the objects are thought of as lying flat.

Russian often chooses different position verbs depending on how something is placed:

• стоять = to stand
• лежать = to lie
• сидеть = to sit

For flat objects like papers, boards, tools, and similar things resting on a surface, лежать is very common.

Since a раскадровка and a хлопушка can naturally be imagined as lying on the ground or on a surface, лежат fits well.

Yes. Хлопушка can have different meanings depending on context.

Common meanings include:

• clapperboard in a film context
• party popper or sometimes firecracker
• other things associated with a snapping or popping sound

In this sentence, because of раскадровка and съёмочная площадка, the film-related meaning is clearly intended: clapperboard.

So context is doing a lot of work here.

Раскадровка means storyboard.

It comes from the idea of dividing something into frames or shots. In film and animation, it refers to a planned sequence of visual scenes.

So even if the English meaning is already known, it helps to notice that this is a standard film-production term in Russian.

Because it agrees with площадке, which is:

• feminine
• singular
• prepositional

The adjective съёмочная must match the noun in gender, number, and case.

So:

• nominative feminine singular: съёмочная площадка
• prepositional feminine singular: на съёмочной площадке

This kind of agreement is one of the most important patterns in Russian grammar.

No, Russian word order is fairly flexible.

The neutral order here is:

• Раскадровка и хлопушка лежат на съёмочной площадке.

But other orders are possible, depending on emphasis:

• На съёмочной площадке лежат раскадровка и хлопушка.
  Emphasis on location: On the set, there are a storyboard and a clapperboard lying there.
• Лежат на съёмочной площадке раскадровка и хлопушка.
  More marked, often literary or context-driven.

For learners, the given order is a very natural and safe one.

It is present tense.

The verb is лежать. Its present-tense forms are:

• я лежу
• ты лежишь
• он / она лежит
• мы лежим
• вы лежите
• они лежат

Since the subject is plural, the sentence uses они лежат.

Strictly speaking, yes: the standard spelling is съёмочной with ё.

In many Russian texts, especially informal ones, ё is often replaced by е, so you may also see:

• съемочной

But the pronunciation and the correct dictionary form use ё.

This matters because ё always carries stress, so it helps with pronunciation:

• съёмочный
• съёмочная
• на съёмочной площадке

Then the verb would become singular.

For example:

• Раскадровка лежит на съёмочной площадке.
  The storyboard is lying on the set.
• Хлопушка лежит на съёмочной площадке.
  The clapperboard is lying on the set.

So the only major change is:

• singular subject → лежит
• plural subject → лежат