77-80 - Stopping Distance and Forces Flashcards
What is stopping distance broken up into?
Thinking and braking distance
What is the definition of stopping distance?
The distance covered between spotting a hazard and coming to a halt
What are the two main factors that affect thinking distance?
Speed
Concentration (affected by drugs, alcohol, tiredness)
What is the definition of thinking distance?
Distance traveled during reaction time
What’s the definition of braking distance?
Distance travelled as car is under braking force
What are the four main factors that affect braking distance?
Speed
Conditions of brakes
Conditions of tyres
Grip (different road surfaces, bad weather)
What is ‘work done’ measured in?
Joules
What is the formula for finding the amount of work done?
w = force * distance
What is the formula for finding gravitational potential energy?
Ep = mass * gravitational field * height
What is the formula for kinetic energy?
Ek = 1/2 * mass * speed^2
What happens to potential energy when an object falls?
It is converted into kinetic energy (Ek)
How might kinetic energy be wasted?
As heat or sound
Why do meteorites form (in terms of forces)?
Meteors have a high Ek
Friction with atmospheric particles = heat energy = burn up
What makes an object elastic?
Its ability to go back to its original shape
What might elastic potential energy be converted to?
Kinetic energy
