Force and Motion I

Vector Addition – Triangle Method Join the tail of the 2nd vector to the head of the 1st vector. Normally the resultant vector is marked with a double arrow. Vector Addition – Parallelogram Method Join the tail of the 2nd vector to the tail of the 1st vector. Normally the resultant vector is marked with … Read more

Vector and Scalar Quantity A scalar quantity is a quantity which can be fully described by magnitude only. A vector quantity is a quantity which is fully described by both magnitude and direction. Vector Diagram The arrow shows the direction of the vector. The length representing the magnitude of the vector. Equal Vector Two vectors … Read more

There are 2 types of pulley, the fixed pulley and the movable pulley. (“Fixed pulley” by César Rincón available under a Creative Commons Attribution-Share Alike 3.0 Unported) (“Movable pulley” by Johjak available under a Creative Commons Attribution-Share Alike 3.0 Unported) In SPM, we will only discuss the fixed pulley. The fixed pulley change the direction, without changing the magnitude of the force. In … Read more

When a man standing inside an elevator, there are two forces acting on him. His weight, (W) which acting downward. Normal reaction (R), acting in the opposite direction of weight. The reading of the balance is equal to the normal reaction (R). Figure below shows the formula to calculate the reading of the balance at … Read more

Free Falling Free falling is a motion under force of gravity as the only force acting on the moving object. Practically, free-falling can only take place in a vacuum. Gravitational Acceleration The gravitational acceleration is the acceleration of an object due to the pull of the gravitational force. It has the unit of ms-2 The … Read more

Crumble Zone The crumple zone increases the reaction time of collision during an accident.This causes the impulsive force to be reduced and hence reduces the risk of injuries. Seat Belt Prevent the driver and passengers from being flung forward or thrown out of the car during an emergency brake. Airbag The inflated airbag during an … Read more

Impulsive Force Impulsive force is defined as the rate of change of momentum in a reaction. Mathematically, we write  F= mv−mu t It is a force which acts on an object for a very short interval during a collision or explosion. Example:A car of mass 1000kg is travelling with a velocity of 25 m/s. The … Read more

Impulse Impulse is defined as the product of the force (F) acting on an object and the time of action (t). Impulse is the product between the force, F with the time of impact, t. Impulse is also defined as the change in momentum. Impulse is a vector quantity. An impulse will cause velocity change … Read more

Types of Forces Friction Friction is the force that oppose motion. There are 2 types of friction that you need to know in SPM: Static friction – friction between 2 surfaces that are not moving relative to each other sliding friction – friction where an object slides or rubs against another surface. Tension When a … Read more

Force A force is push or pull exerted on an object. Force is a vector quantity that has magnitude and direction. The unit of force is Newton ( or kgms-2). Unbalanced Force/ Resultant Force When the forces acting on an object are not balanced, there must be a net force acting on it. The net … Read more