Force and Motion

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

Rocket Mixture of hydrogen and oxygen fuels burn in the combustion chamber. Hot gases are expelled through the exhausts at very high speed . The high-speed hot gas produce a high momentum backwards. By conservation of momentum, an equal and opposite momentum is produced and acted on the rocket, pushing the rocket upwards. Jet Engine … Read more

Elastic Collision Elastic collision is the collision where the kinetic energy is conserved after the collision. Total Kinetic Energy before Collision= Total Kinetic Energy after Collision Additional notes: In an elastic collision, the 2 objects separated right after the collision, and the momentum is conserved after the collision. Total energy is conserved after the collision. … Read more

Principle of Conservation of Momentum The principle of conservation of momentum states that in a system make out of objects that react (collide or explode), the total momentum is constant if no external force is acted upon the system. Sum of Momentum Before Reaction= Sum of Momentum After Reaction Formula Example – Both Objects are … Read more

Momentum Momentum is defined as the product of mass and velocity. Momentum is a vector quantity. It has both magnitude and direction. The SI unit of momentum is kgms-1 Formula: Example:A student releases a ball with a mass of 2 kg from a height of 5 m from the ground. What would be the momentum … Read more