Lesson 2: Kinematics
Understanding Kinematics
Kinematics is the study of motion without considering its causes. It includes concepts such as displacement, velocity, acceleration, and time.
Velocity is just the speed of something in a certain direction. We know that speed is equal to distance over time. Distance is a scalar quantity, so speed is a scalar quantity. If we can make distance a vector quantity, then it will become velocity because velocity is a vector quantity. So distance with direction is displacement. So displacement over time is equal to velocity. Velocity is measured in meters per second.
Example Problems
Example problem:
A car is stopped at a red light. When the light turns green, the car travels for 30 meters in 10 seconds. What is its velocity?
Solution:
Velocity = Distance / Time
= 30 m / 10 s
= 3 m/s
Another example:
A car accelerates uniformly from rest to 20 m/s in 5 seconds. What is the acceleration?
Solution:
Acceleration = Change in velocity / Time
= (20 m/s - 0 m/s) / 5 s
= 4 m/s²