Kinematics is the area of mechanics that uses words, pictures, figures, graphs, and equations to explain how objects move. The goal of this project is to create challenging mental models that capture how real-world objects move.
In this lesson, we’ll look into the terminology used to explain how objects move. Scalars, vectors, distance, displacement, speed, velocity, and acceleration are a few examples.
SCALARS AND VECTORS
Mathematics underpins the notions and principles of physics. There are two types of mathematical quantities that are used to describe how objects move. Either a vector or a scalar amount applies. These two categories can be separated from one another by the way they are defined differently.
Scalars are objects that solely have magnitude and no direction. They can be divided by another scalar quantity and have only one dimension. The number [magnitude] and units of these quantities can be used to represent them. Examples include weight, length, temperature, and time.
Quantities with both magnitude and direction are called vectors. Because of their multiple dimensions, they cannot be split by another vector quantity. The number [magnitude], units, and direction of these quantities can all be used to represent them. Examples include distance traveled, force, speed, acceleration, and momentum.
DISTANCE AND DISPLACEMENT
Displacement and distance are two terms that can have the same meaning while also having different connotations.
Distance, a scalar quantity, measures the amount of space an object has traveled through while in motion. It evolves as the path changes and is dependent on the path traveled (providing information on the entire path traveled by an object).
The term “displacement” refers to a vector quantity that measures how far an object has moved from its original position. It depends on the quickest path a body can take to get from one place to another, as well as the direction it travels in.
SPEED AND VELOCITY
Despite their similarities, velocity and speed have two separate definitions.
Speed is a scalar quantity that describes how quickly something is moving. It can also be considered as the speed at which something is moving. An object that is moving quickly has a higher speed than an object that is travelling slowly. A stationary item has no speed.
The rate at which an object varies with location is referred to as velocity, which is a vector quantity. An object’s direction must be mentioned in order to convey an object’s velocity.
For instance, merely stating that an item is moving at 50 m/s is insufficient. One needs to provide the direction, such as 50 m/s east.
Average Speed and Average Velocity Calculation
The following formula can be used to get the average speed:
The average speed can be computed using the following formula:
Average Speed = distance traveled / time of travel
In contrast, the average velocity is computed using the formula
Average Velocity = displacement / time
Question
While on a holiday, Priscilla Forson travelled a distance of 30km. her trip took 6 hours. What is her average speed.
V = 30km / 6hr = 5km/hr
AVERAGE SPEED AND INSTANTANEOUS SPEED
It is appropriate to distinguish between average speed and instantaneous speed since moving things frequently change their speed while they are in motion.
The speed at any particular moment is called the instantaneous speed.
The average of all instantaneous speeds is known as the average speed. only by calculating the distance/time ratio.
ACCELERATION
Acceleration is the final numerical value for this segment. There are numerous meanings linked with acceleration.
The rate at which an item changes its velocity is known as acceleration, a vector quantity. If an object’s velocity changes, it accelerates.
CONSTANT ACCELERATION
An object’s velocity may occasionally change by the same amount every second. A continuous acceleration is what is being described here.
Equation can be used to determine any object’s average acceleration over a certain amount of time.
Average acceleration = change in velocity / time
DIRECTION OF AN ACCELERATION VECTOR
Because acceleration is a vector quantity, it has a direction. An acceleration vector’s direction is determined by two factors:
• Whether the object is going faster or slower;
• Whether it is travelling in a positive or negative direction.
The usual rule for calculating acceleration is that it should be in the opposite direction of motion if an item is slowing down.
This general principle is applicable whether the acceleration is going up, down, right, or left, regardless of the sign of the acceleration.