forces and pressure

What is a force?

A push or a pull exerted on an object, measured in Newtons (N).

What are the two main categories of forces?

1. Contact Forces: Objects must be touching (e.g., friction, air resistance).
2. Non-contact Forces: Objects do not need to be touching (e.g., gravity, magnetism, static electricity).

What is a resultant force?

The single overall force acting on an object, found by combining all the individual forces acting upon it.

What instrument is used to measure force?

A Newton meter (or spring balance).

What is the formula for calculating Pressure?

Pressure = \frac{Force}{Area} (P = \frac{F}{A}).

What is the standard unit for Pressure?

Pascals (Pa), which is the same as Newtons per square meter (N/m^{2}).

How does area affect pressure if the force remains the same?

The larger the area, the lower the pressure. The smaller the area, the higher the pressure (P \propto \frac{1}{A}).

Why do snowshoes help you walk on deep snow?

They have a large area, which spreads your weight (force) over a bigger surface, reducing the pressure on the snow.

What is Hooke's Law?

The extension of a spring is directly proportional to the force applied to it (F = k \times x), until the limit of proportionality is reached.

How does water pressure change with depth?

Pressure increases with depth because the weight of the water above pushing down increases.