What is equivalent to 1 joule?

One joule is defined as the amount of energy transferred when a force of one newton is applied over a distance of one meter. This is mathematically represented as work done (or energy) being equal to force multiplied by distance:

[ \text{Work (J)} = \text{Force (N)} \times \text{Distance (m)} ]

Thus, when force is measured in newtons and distance in meters, the product, which is one joule, can be expressed as one newton meter. This relationship highlights the direct correlation between force and distance in producing energy.

The other choices do not accurately reflect the definition of a joule. A newton on its own is a unit of force, while a newton second refers to momentum and is related to mass and velocity, and a meter per second measures speed. None of these correctly convey the concept of energy as the product of a force applied over a distance, making the newton meter the equivalent of one joule.