P2.1 - Forces and their effects Flashcards
Whenever two objects interact, the forces they exert on each other are…
Equal and Opposite.
What is a resultant force?
When a number of forces are acting on an object, they may be replaced by a single force, the resultant force.
What can an resultant force change about an object?
Its state of rest or motion.
What will happen when the resultant force acting on a stationary object is zero?
The object will remain stationary.
What will happen when the resultant force acting on a stationary object is NOT zero?
The object will accelerate in the direction of the resultant force.
What will happen when the resultant force acting on a moving object is zero?
The object will continue to move at the same speed and in the same direction.
What will happen when the resultant force acting on a moving object is NOT zero?
The object will accelerate in the direction of the resultant force.
What is the acceleration of an object determined by?
The resultant force acting on the object and the mass of the object.
What is velocity?
The speed of a object in a given direction.
What are most resistive forces caused by?
Air Resistance.
What is stopping distance?
The sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance).
What can a drivers reaction time be affected by?
Tiredness, drugs and alcohol.
What happens when the brakes are applied?
Work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increase.
What factors can affect braking distance?
Adverse road and weather conditions (including wet or icy conditions) and poor condition of the vehicle.
The faster an object moves through a liquid…
…the greater the frictional force that acts on it.