Dynamics 🚙

• Terminal velocity is when the forces acting on the object are balanced so it is no longer accelerating.
• Energy is conserved: Ew = Fd.
• Kinetic energy is conserved: Ek = 0.5mv^2.
• A geostationary satellite is 35800km high and takes 24hrs to orbit the earth, hence the name geostationary as it moves with the rotation of the Earth over the equator.
• Resultant forces:
• One technology deriving from space exploration is memory foam, which was initially used to improve crash protection, but was then lately repurposed for products like mattresses, pillows, cars, and furniture.
• The earth is 46.5 billion light years away from the edge of the universe.
• As the height of the satellite increases, the orbital period also increases as the journey it takes to orbit is longer, while it remains at the same speed.
• Free fall is any object where the only force acting on it is gravity.
• Gravitational field strength in Newtons per kilo (NKg-1).
• For every force, there is an equal and opposite reaction.
• The earth is 0.000015606 light years from the sun.
• The return to Earth is also dangerous as there is a very large friction force between the space capsule and the atmosphere, which releases huge amounts of heat energy.
• Power is conserved: P = E / t.
• Downhill: Loss of gravitational potential energy = gain of kinetic energy, 0.5mv^2 = mgh.
• The earth is 4.246 light years away from the nearest star.
• Our current understanding of the universe is a result of our continual observation and exploration of space.
• Projectile motion is two separate motions: constant horizontal velocity and constant vertical acceleration.
• Weight = m * g.
• Newton's first law: an object will remain at rest or continue to move at a constant velocity unless acted upon by a force.
• Force = mass * acceleration.
• Space travel can be dangerous, as in stages like Lift-off, large volumes of fuel are released, which is a risk for explosions which have happened in the past.
• The earth is 25,000 light years away from the next galaxy.
• Space exploration led to the creation of satellites, which have widened our understanding of Earth as they can be used for weather forecasting, where satellite images are used to predict the weather for periods of time.
• Gravitational potential energy is conserved: Ep = mgh.
• A light year is the distance that light travels in one year.
• Loss of kinetic energy equals gain of gravitational potential energy, represented by the equation mgh = 0.5mv^2.
• Average speed is the average rate of which something travels a certain distance over a certain amount of time, represented by the equation v bar = d/t.
• Instantaneous speed is the speed at one certain point of a journey, compared to average speed which is for the overall journey, represented by the equation v = d/t.
• Acceleration is the change of velocity in one second, represented by the equation a = (v-u) / t.
• Deceleration is the change of velocity in one second, represented by the equation a = (v-u).
• A scalar quantity has only magnitude, and no direction, while a vector quantity has both direction and magnitude.
• The difference between distance and displacement is that displacement has both direction and magnitude, while distance only has its magnitude.
• The difference between velocity and speed is that speed is a scalar, which means that it has no description in which direction the object is moving at, while velocity has both magnitude and direction, which means that moving backwards is - ms-1, and moving forwards is ms-1.
• Types of velocity-time graphs include acceleration, velocity, speed, and distance travelled.
• To find the distance travelled from speed time graphs, find the area underneath the lines.
• To find the displacement in a velocity time graph, it is very similar - but make sure it is a velocity time graph and not a speed time graph.
• Acceleration is the gradient of the line on a velocity time graph.