Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The motion of an object can be classified as slow or fast by comparing the distance covered by it in a given interval of time.
An object that covers a larger distance in a given time is said to be faster, while an object that covers a smaller distance in the same time is said to be slower.
The most convenient way to find out which of the two or more objects is moving faster is to compare the distance moved by them in a unit time. This quantity is called .
Average Speed is defined as the total distance covered divided by the total time taken. In common usage, the term 'speed' usually refers to average speed.
If the speed of an object moving along a straight line keeps changing, its motion is said to be .
If an object moving along a straight line maintains a constant speed, it is said to be in .
The basic unit of time is the () and the basic unit of speed is (metres per second).
Speed can also be expressed in other units such as (kilometres per hour) or (metres per minute).
📐Formulae
💡Examples
Problem 1:
A car travels a distance of in . What is the speed of the car?
Solution:
Given: Distance , Time . Using the formula , we get .
Explanation:
The speed of the car is calculated by dividing the total distance by the total time taken, resulting in .
Problem 2:
Comparison of two motions: Object A covers in , and Object B covers in . Which one is faster?
Solution:
Speed of Object A: . Speed of Object B: . Since , Object A is faster.
Explanation:
By calculating the speed (distance per unit time) for both objects, we can directly compare their rates of motion. Object A has a higher speed, thus it is faster.
Problem 3:
Convert a speed of into .
Solution:
To convert to , multiply by : .
Explanation:
Since and , the conversion factor is , which simplifies to .