forces Flashcards
(15 cards)
What is a scalar quantity?
A quantity with magnitude but not direction.
What is a vector quantity?
A quantity with magnitude and direction.
Give some examples of scalar quantities
-Distance
-Speed
Give some examples of vector quantities
-Velocity
-Displacement
What is newtons first law of motion?
An object will continue to be at rest or a steady
speed unless acted on by a resultant force
What is newtons second law of motion?
Acceleration is proportional to the resultant force,
and inversely proportional to the mass
What is newtons third law of motion?
When two objects interact, the forces are equal in size,
but opposite in direction
What is stopping distance?
The sum of thinking distance and breaking distance
What is thinking distance?
Thinking distance is the distance travelled while a driver reacts to a situation
What factors affect thinking distance?
-tiredness
-drugs
-alcohol
-distractions e.g. mobile phone
What is breaking distance?
Braking distance is the distance travelled while the brakes are applied
What factors affect stopping distance?
-the condition of the road
-the weather
-the condition of the car
-the mass of the vehicle
Why do breaks glow?
When a force is applied to the brakes, work is done by friction. This decreases the kinetic energy store of the car, but increases the thermal store of the brakes and surroundings, increasing the temperature
How does momentum work?
In a closed system, momentum is conserved; the total momentum before a collision is equal to the total momentum after a collision
What is the relationship in a change of momentum?
Force and time are inversely proportional; if you can increase
the time of a collision you can decrease the force involved
