Bivariate Analysis

Friction and Normal Friction

Friction is a force that resists motion between two surfaces in contact.
In some contexts, it can be broken down into static friction and kinetic friction, depending on whether the objects are in motion relative to each other.
The force of friction is proportional to the normal force.
The normal force is the force exerted by a surface to support the weight of an object resting on it, acting perpendicular to the surface.
The concepts of coefficient of friction and frictional force are essential, where the latter equals the product of the former and the normal force.

Limiting friction refers to the maximum friction that can be generated between two static surfaces. After this point, motion will commence.
It can be calculated using the formula: limiting friction = coefficient of friction x normal contact force.

A moment is the turning effect of a force around a pivot point.
It’s given by the equation: moment = force x distance, where distance is the perpendicular distance from the pivot to the point where force is applied.
The principle of moments, which states that for an object in equilibrium, the sum of clockwise moments about a pivot is equal to the sum of anticlockwise moments.

Statistics encompasses a wide array of topics, from data representation to measures of central tendency and dispersion.
Data representation includes flexible methods like tables, graphs, pie charts etc.

The limits of a list of numbers are the smallest and largest values in the list.
Boundaries of a class are the numbers that divide classes. In practice, they are usually halfway between the upper limit of one class and the lower limit of the next class.
Calculating class boundaries can be crucial when creating frequency tables or histograms.

Class-width is the difference between the upper boundary and the lower boundary of a given class in a frequency distribution table.
The mid-age or midpoint of a class is the average of the upper and lower boundaries.

This is a statistical distribution that shows the distribution of ages in a population.

Histograms are visual representations of data distribution over a continuous interval or certain time period.

Central tendency includes measures like mean, median and mode.
Dispersion measures include range, variance, and standard deviation. They give insight into how spread out a set of values is around the central value.

Standard deviation is a measure of how much variance there is in a set of numbers.
Mean is the average of a set of numbers.
Median is the middle value when a set of numbers is arranged in order.

Probability is a statistical concept that measures the possibility of a specific event happening.

Venn diagrams are illustrations with overlapping circles that depict how much different groups have in common.

A tree diagram is a new kind of diagram that systematically illustrates all possible outcomes of an event.

Conditional probability is the likelihood of an event or outcome based on the occurrence of a previous event or outcome.

Bivariate analysis is a statistical method that helps you study relationships (correlation) between two variables.