Твой рюкзак весит меньше, но его вес всё равно чувствуется после долгой прогулки.

Yes. Твой is the informal singular form of your.

Russian distinguishes:

• твой = your, when speaking to one person informally
• ваш = your, when speaking politely or to more than one person

So Твой рюкзак means your backpack when talking to a friend, child, family member, etc.

Also, твой agrees with рюкзак, which is masculine singular, so the masculine form твой is used.

Because рюкзак is the subject of the verb весит.

In this sentence:

• Твой рюкзак = the thing doing the action
• весит = weighs

Subjects normally appear in the nominative case, and the nominative singular form here is рюкзак.

So:

• рюкзак = nominative
• рюкзака would be genitive/accusative in some contexts
• рюкзаку would be dative

Весит меньше means weighs less, while легче means is lighter.

They are close in meaning, but the focus is a little different:

• весит меньше focuses on actual weight
• легче describes the object as lighter in comparison

So:

• Твой рюкзак весит меньше = your backpack weighs less
• Твой рюкзак легче = your backpack is lighter

Both can work in many situations, but весит меньше sounds more directly about measurable weight.

Because the comparison is left implicit.

Russian often omits чем when the thing being compared is understood from context.

So весит меньше means:

• weighs less
• implicitly: than the other one / than before / than mine, etc.

If you wanted to say the full comparison, you could say something like:

• Твой рюкзак весит меньше, чем мой.
  = Your backpack weighs less than mine.

Without чем, the sentence still sounds natural if the comparison is already clear.

Yes. In Russian, его can mean:

• his
• its for masculine or neuter nouns

Since рюкзак is a masculine noun, его вес means its weight.

Russian does not usually have a separate everyday possessive word exactly like English its. Instead, it uses:

• его for masculine/neuter
• её for feminine
• их for plural

So:

• рюкзак — его вес = backpack — its weight
• сумка — её вес = bag — its weight

Всё равно means something like:

• all the same
• still
• nevertheless

In this sentence, it adds the idea that even though the backpack weighs less, the weight is still noticeable.

So the logic is:

• it is lighter,
• but even so, you can still feel the weight after a long walk.

This phrase is very common in Russian and often connects two ideas where the second one remains true despite the first.

Because чувствуется means is felt or can be felt, not feels in the active sense.

Compare:

• чувствует = feels, senses
  Example: Он чувствует боль. = He feels pain.
• чувствуется = is felt, can be felt, is noticeable
  Example: Усталость чувствуется. = The tiredness is noticeable / can be felt.

In your sentence, его вес is not doing the feeling. Instead, the weight is felt by someone. That is why Russian uses the reflexive form чувствуется.

So:

• его вес всё равно чувствуется
  = its weight is still felt / you can still feel its weight

Not exactly in the formal grammar sense, but it often works like a passive expression in English.

Literally, Russian uses a reflexive verb:

• чувствовать = to feel
• чувствоваться = to be felt / to be noticeable

So English often translates it with a passive-style phrase:

• вес чувствуется = the weight is felt
• запах чувствуется = the smell can be sensed
• напряжение чувствуется = the tension is noticeable

This is a very common Russian pattern.

It is the genitive case because the preposition после always takes the genitive.

So:

• после = after
• прогулка = walk
• after после, it becomes прогулки

The adjective must match too:

• долгая прогулка = a long walk
• после долгой прогулки = after a long walk

So both words change to genitive singular feminine:

• долгой
• прогулки

Because it has to agree with прогулки in:

• gender: feminine
• number: singular
• case: genitive

Dictionary form:

• долгая прогулка = long walk

After после, genitive is required:

• после долгой прогулки

This is standard adjective agreement in Russian:

• adjective changes form to match the noun it describes

Но means but and introduces contrast.

The sentence structure is:

• Твой рюкзак весит меньше = Your backpack weighs less
• но его вес всё равно чувствуется = but its weight is still felt

The contrast is:

• lower weight
• yet still noticeable after a long walk

As for word order, Russian is more flexible than English, but this order sounds natural and clear. Placing всё равно before чувствуется helps emphasize the idea of still / nevertheless.

Yes. Долгой simply adds extra detail: after a long walk instead of just after a walk.

So:

• после прогулки = after a walk
• после долгой прогулки = after a long walk

The adjective gives more context and helps explain why even a lighter backpack can still be felt.