Motion

• Motion 1: Motion is a scalar.
• Displacement is a straight line from start to finish, making it a vector.
• Speed is calculated as distance divided by time.
• Velocity is speed with direction, making it a vector.
• The gradient of a distance-time graph shows speed.
• Acceleration is calculated as change in velocity divided by time taken, represented by the equation a = (Δv/t).
• To investigate changing force on a constant mass, add a 10g mass to the weight stack, holding it so it doesn’t pull the car but the string is fully extended.
• Release the car and time how long it takes for the car to travel across the bench.
• To investigate changing mass with a constant force, attach a 10g mass on top of the toy car, using either the Blu-Tac or rubber bands.
• Pull the car back to the starting chalk line.
• Terminal velocity is the maximum speed of an object, reached when the forces moving the object are balanced by its frictional forces.
• When an object falls freely, its acceleration is 9.8 m/s2.
• Inertia is the measure of an object's tendency to remain at rest or moving at constant speed, represented by the equation inertia mass = force/acceleration.
• Newton's first law states that if the resultant force is zero, then the object is stationary or moving at the same speed along a straight line.
• Constant speed is achieved when the resistive force equals the driving force.
• Inertia mass is a measure of how hard it is to change an object's velocity.
• Newton's second law states that the acceleration of an object is proportional to the resultant force acting and inversely proportional to the mass of the object, represented by the equation F = ma.
• Newton's third law states that when two objects interact, the forces exerted are equal and opposite.
• Braking distance is proportional to the square of velocity and mass, represented by the equation Braking distance = (0.5*mass(kg)* velocity2 (m/s))/braking force.
• Thinking distance is proportional to speed and minimum distance between cars, represented by the equation Momentum = mass * velocity.
• Change of momentum is calculated as force divided by time, represented by the equation Force = change of momentum/time.
• The equation for force is (mass (kg) x change of velocity (m/s) ) divided by time taken (s).
• Crumble zones are designed to lessen the force of impact.
• Seat belts stop the wearer from going forward when the car stops.
• When two vehicles collide, the impact force is exerted as equal and opposite impact forces on each other at the same time.
• The equation of stopping distance is braking distance + thinking distance.
• Total momentum is conserved after impact, meaning the momentum before impact is the same as the total momentum after impact.
• In the centre of mass experiment, a hole is put in one corner of the card from a rod, and a plump line is used to draw a vertical line on the card.
• Cushioned surfaces help by increasing the duration of impact, reducing momentum, and reducing impact force.
• When impact time is increased, the impact force lowers.
• The experiment involves hanging a card on different holes.
• Child car seats reduce deaths and serious injuries of children in cars.
• The helmet is designed to increase impact time.
• Airbags help by spreading the force of impact across the upper part of the body, increasing impact time, and lowering the effect of force.
• The centre of mass is the point through which the weight of an object can be considered to act.
• Seat belts are placed across the chest to spread out the force.
• The aim of the investigation is to investigate the relationship between force and extension for a spring.
• Thinking distance is proportional to speed.
• A closed system is one where no external forces act on the system.
• Braking distance is proportional to speed squared.