physics

Nuclear gravity bomb

Nuclear gravity bomb is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Nuclear gravity bomb rather than just read about it. In short: A nuclear gravity bomb is a nuclear weapon intended to be dropped from an aircraft, with no propulsion. It may be an unguided bomb or a glide bomb.

Key takeaways

Nuclear gravity bomb belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Nuclear gravity bomb to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Nuclear gravity bomb from memory before moving on to harder problems.

Reference excerpt

A nuclear gravity bomb is a nuclear weapon intended to be dropped from an aircraft, with no propulsion. It may be an unguided bomb or a glide bomb. This is in contrast to nuclear-armed air-launched cruise missiles, air-launched ballistic missile, and air-to-air missiles. As of 2025, nuclear gravity bombs are used in the arsenals of the United States, Russia, Israel, India, and Pakistan, but not in the arsenals of China, France, the United Kingdom, and North Korea.

History

Nuclear gravity bombs were the first nuclear weapons constructed and only nuclear weapons to ever be used in war: at the end of World War II, the US attacked Hiroshima with a Little Boy bomb and attacked Nagasaki with a Fat Man bomb. Nuclear gravity bombs initially dominated the Cold War's nuclear arms race, due to reliance on strategic bombers. In 1954, the US' Strategic Air Command anticipated it would deliver 750 bombs against the Soviet Union's 150 bombs. The introduction of intercontinental ballistic missiles, submarine-launched ballistic missiles, and advanced cruise missiles decreased the strategic relevance of gravity bombs. Nuclear gravity bombs were also a primary method of atmospheric nuclear testing. This allowed the testing of larger thermonuclear weapons without ground contamination causing fallout. Examples include the Soviet RDS-37 and Tsar Bomba, Chinese Project 596L and Project 639, and US Ivy King (non-thermonuclear). The first nuclear weapons put into production by a country are typically gravity bombs, including the US Mark III (Fat Man), the Soviet Union's RDS-1, the UK Blue Danube and French AN-11. Nuclear gravity bombs were also historically used as tactical nuclear weapons, such as US Mark 7, Soviet RDS-4, UK WE.177, French AN-52, and Chinese Kuangbiao-1.

Current usage The US currently maintains the B61 and B83 nuclear bombs. The B61 has strategic variants, up to 400 kilotons, intended for delivery by B-2 Spirit and B-21 Raider bombers, while its tactical variants can also be delivered by F-15, F-16, F/A-18, and F-35 fighters. The B61 is also forward-deployed to airbases in European NATO countries, where it is also intended for delivery by host country Panavia Tornados. The B61 Mod 12 has an enhanced tail kit and glide bomb capability. The B83, at 1.2 megatons, has been the largest weapon in the US nuclear arsenal since the 2011 retirement of the B53 nuclear bomb. In 2025, Commander of US Strategic Command General Anthony J. Cotton claimed Russian Tu-95 and Tu-160 strategic bombers could deliver nuclear gravity bombs, but a Federation of American Scientists report deemed this practically unlikely. Russia can deploy tactical nuclear bombs from its Tu-22 M3, Su-24, Su-34, and MiG-31K aircraft. Russia is believed to forward-deploy nuclear gravity bombs to Belarus, where Belarusian Air Force crews are trained to deliver them via Su-25 aircraft. Israel is believed to designate nuclear squadrons of F-15I and F-16I fighters at Tel Nof Airbase and Hatzerim Airbase. There is also speculation that its F-35I fighters may be capable of deploying nuclear weapons. India operates Dassault Mirage 2000, SEPECAT Jaguar, and Dassault Rafale fighters in nuclear bomb delivery roles. It intends to fully replace its Jaguars with HAL Tejas Mk2 multirole fighters by 2035. Pakistan operates Dassault Mirage III and Mirage 5 fighters for nuclear bomb delivery, with unconfirmed reports they also modified F-16 fighters procured from the US. It has also been speculated CAC/PAC JF-17 Thunder aircraft will take over the Pakistan Air Force nuclear role, although possibly only with the Ra'ad cruise missile series.

See also Nuclear weapons delivery Strategic bomber B61 nuclear bomb Air-launched cruise missile Air-launched ballistic missile Air-to-air missile

References

Illustrations

Worked examples

Example 1 — a first encounter with Nuclear gravity bomb

Start with the simplest possible case. Write down what Nuclear gravity bomb claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Nuclear gravity bomb before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Nuclear gravity bomb ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Nuclear gravity bomb

In research: Nuclear gravity bomb appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Nuclear gravity bomb in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Nuclear gravity bomb is common in secondary-school and first-year university syllabi. It links to neighbouring topics Nuclear bombs, Nuclear weapons, Strategic bombers, so understanding it makes those chapters shorter.
In everyday life: Look for Nuclear gravity bomb outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Nuclear gravity bomb in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Nuclear gravity bomb means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Nuclear gravity bomb out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Nuclear gravity bomb in simple terms?

A nuclear gravity bomb is a nuclear weapon intended to be dropped from an aircraft, with no propulsion. It may be an unguided bomb or a glide bomb.

Why does Nuclear gravity bomb matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Nuclear gravity bomb?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Nuclear gravity bomb.