Weight

Definition

Weight is the force exerted on an object due to gravity. It is calculated as the product of mass and gravitational acceleration.

5 Must Know Facts For Your Next Test

1. Weight is a vector quantity with both magnitude and direction, acting towards the center of the Earth.
2. The formula for weight is $W = mg$, where $W$ is weight, $m$ is mass, and $g$ is gravitational acceleration (approximately $9.8 \frac{m}{s^2}$ on Earth).
3. Weight varies depending on the gravitational field strength of a celestial body; an object weighs less on the Moon than on Earth.
4. The weight of an object can be measured using a spring scale or a digital scale calibrated for gravitational force.
5. Normal force often counteracts weight in scenarios involving surfaces to prevent objects from accelerating through them.

Review Questions

• What formula is used to calculate the weight of an object?
• Why does an object's weight change when it moves from Earth to another planet?
• How does normal force relate to an object's weight when it is resting on a flat surface?

Related terms

Mass:

A measure of the amount of matter in an object, typically measured in kilograms (kg), independent of gravity.

Gravitational Acceleration: The acceleration due to gravity experienced by an object, approximately $9.8 \frac{m}{s^2}$ near Earth's surface.

Normal Force:

A support force exerted upon an object that is in contact with another stable object, acting perpendicular to the surface.