Motion and Forces Flashcards
What is a scalar quantity?
A quantity that only has magnitude and not direction
What is a vector quantity?
A quantity that has magnitude and direction
On a speed time graph, what does a horizontal line represent?
A constant speed
What does the area of the section underneath a speed time diagram represent?
Distance travelled
What is Newton’s first law?
An object in motion will stay in motion or an object at rest will stay at rest unless acted upon by an unbalanced force
What is Newton’s second law?
F=MA / Force is directly proportional to the mass of an object x it’s acceleration
What is Newton’s third law?
Every action has an opposite and equal reaction
What is the rule of circular motion?
An object will move in a circular path if his if it’s motion is at right angles to a force that acts inwards along the radius (centripetal force)
What is centripetal force?
Force acting inwards along the radius
What is weight?
The force a body experiences due to it’s mass and the gravitational field that it’s in
What is mass?
Measure of the amount of matter contained in a 3D space
How long does it take (on average) for a person to react to a stimulus?
Between 0.20s and 0.25s
How do you calculate stopping distance?
Thinking distance + braking distance
What do safety features in modern cars do?
Air bags, crumple zones and seat belts are all designed to absorb some of the impact of the crash. They also make the time of the crash longer (this means that the force of the crash is smaller because of the equation force= change in momentum/time)
What factors affect thinking distance?
- Alcohol/drugs
- Age
- Distractions
- Tiredness
