Heavy Things Sink Notes & Questions | Class 1 Physics | Drishti OS

Heavy Things Sink

NCERT anchor: NCERT Looking Around Class 1 — Theme: Water Around Us (why heavy objects sink)

What you'll learn

Heavy, solid things like a stone, a coin, or a key usually sink.
Metal spoons and keys sink because they are heavy for their size.
We keep heavy sinking things away from open water for safety.

Key concepts

1. Heavy objects in water

Level 1 (Verbal): A stone dropped in a pond goes straight down — it sinks.

Level 2 (Symbolic): Heavy + solid = usually sinks.

Visual: A key resting at the bottom of a glass tumbler.

2. Metal things

Verbal: A steel spoon, a coin, and a key are heavy for their size, so they sink.

Symbolic: Metal objects are usually dense and sink in water.

Visual: Coins settled at the bottom of a fountain.

3. Safety near water

Since heavy things sink and stay down, we never go looking for a sunken toy alone — always call a grown-up.

Worked example

Dropped keys in a bucket

Step 1 — A bunch of keys falls into a bucket of water.
Step 2 — The keys are heavy metal.
Step 3 — They sink straight to the bottom of the bucket.
Step 4 — A grown-up carefully takes them out.
Answer: the keys sink because they are heavy metal.

Common mistakes

Mistake	Why	Fix
Thinking all metal always sinks	A large hollow steel ship still floats	At Class 1, focus on solid small metal objects sinking
Believing heavy always means big	A small coin is heavy for its size and sinks	Heaviness is about weight for the size, not just size
Reaching into deep water alone for a sunk item	Unsafe for children	Always ask a grown-up for help

Quick check

Name two heavy things that sink in water.
What happens when you drop a coin into a glass of water?
Should you go alone into deep water to find a sunk toy?
Stretch: A small pebble sinks. Will a big rock also sink? Why?

Revision tip: Say aloud: 'Heavy and solid usually means it sinks.'

Open the Practice tab for graded questions on Heavy Things Sink.

Heavy Things Sink