Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Kinematics is the study of motion without considering its causes, focusing on parameters like displacement (), velocity (), and acceleration ().
Scalars are quantities with magnitude only (e.g., distance, speed), whereas Vectors have both magnitude and direction (e.g., displacement, velocity, force).
Instantaneous velocity is the velocity at a specific moment in time, defined as the derivative of displacement with respect to time: .
Acceleration is the rate of change of velocity over time: .
Newton's First Law (Inertia): An object will remain at rest or move with constant velocity unless acted upon by a non-zero resultant force ().
Newton's Second Law: The resultant force acting on an object is equal to the rate of change of momentum, commonly expressed as when mass is constant.
Newton's Third Law: If body A exerts a force on body B, body B exerts a force of equal magnitude and opposite direction on body A ().
Weight () is the force of gravity acting on an object: , where on Earth.
📐Formulae
💡Examples
Problem 1:
A car travelling at comes to a complete stop over a distance of under uniform deceleration. Calculate the acceleration of the car.
Solution:
Explanation:
We use the kinematic equation . Here, , (stop), and . Rearranging for : .
Problem 2:
A wooden crate of mass is pushed across a floor with a horizontal force of . If the force of friction is , find the acceleration of the crate.
Solution:
Explanation:
First, calculate the net force: . Using Newton's Second Law (), we find .