1. Motion (Kinematics)
Motion is the study of how objects move without looking at the cause.
Speed vs. Velocity: * Speed is scalar (distance/time).
o Velocity is vector (displacement/time). It includes direction.
Acceleration ($a$): The rate of change of velocity.
$$a = \frac{v - u}{t}$$
(Where $v$ = final velocity, $u$ = initial velocity, $t$ = time)
Motion Graphs (High Priority for Exams)
1. Distance-Time Graphs:
o Gradient = Speed.
o Flat line = Stationary.
2. Velocity-Time Graphs:
o Gradient = Acceleration.
o Area under the graph = Distance travelled.
o Flat line = Constant velocity.
2. Forces and Dynamics
Forces change the speed, direction, or shape of an object.
Newton’s Second Law: Force is mass times acceleration.
$$F = m \times a$$
Weight ($W$): The force of gravity acting on a mass.
$$W = m \times g$$
(On Earth, $g \approx 9.8$ or $10\text{ m/s}^2$)
Terminal Velocity: When an object falls, air resistance increases until it equals the weight. The
resultant force becomes zero, and the object falls at a constant speed.
Circular Motion
When an object moves in a circle at a constant speed, its velocity is changing because its direction is
changing. This means it is accelerating toward the center of the circle (Centripetal force).
Hooks Law (Deformation)
Forces can stretch objects.
$$F = k \times x$$
(Where $k$ is the spring constant and $x$ is extension)
Motion is the study of how objects move without looking at the cause.
Speed vs. Velocity: * Speed is scalar (distance/time).
o Velocity is vector (displacement/time). It includes direction.
Acceleration ($a$): The rate of change of velocity.
$$a = \frac{v - u}{t}$$
(Where $v$ = final velocity, $u$ = initial velocity, $t$ = time)
Motion Graphs (High Priority for Exams)
1. Distance-Time Graphs:
o Gradient = Speed.
o Flat line = Stationary.
2. Velocity-Time Graphs:
o Gradient = Acceleration.
o Area under the graph = Distance travelled.
o Flat line = Constant velocity.
2. Forces and Dynamics
Forces change the speed, direction, or shape of an object.
Newton’s Second Law: Force is mass times acceleration.
$$F = m \times a$$
Weight ($W$): The force of gravity acting on a mass.
$$W = m \times g$$
(On Earth, $g \approx 9.8$ or $10\text{ m/s}^2$)
Terminal Velocity: When an object falls, air resistance increases until it equals the weight. The
resultant force becomes zero, and the object falls at a constant speed.
Circular Motion
When an object moves in a circle at a constant speed, its velocity is changing because its direction is
changing. This means it is accelerating toward the center of the circle (Centripetal force).
Hooks Law (Deformation)
Forces can stretch objects.
$$F = k \times x$$
(Where $k$ is the spring constant and $x$ is extension)
