P2.3 Motion and Forces Flashcards
What is velocity?
Velocity is speed in a stated direction.
How do you calculate acceleration?
Acceleration= change in velocity/time
How do you calculate distance on a velocity time graph?
The area under a velocity time graph is equal to the distance the object has travelled.
What is a force?
A force is a push or a pull. Forces make objects change speed. It is a vector quantity.
What happens when to objects interact?
When two objects interact, they exert forces onto each other. The forces are called action and reaction forces. The pair is called an action-reaction pair.
What is resultant force?
The total force that results from two or more forces acting on a single object. If in the same direction, they a re added together, if in opposite directions they are subtracted from each other.
What happens if the resultant force is zero?
The movement of the object doesn’t change, it either remains at a constant velocity or will remain stationary.
What does the size of acceleration depend on?
- The size of the force (for objects with the same mass)
- The mass of the object (for the same force).
What is the equation for force?
Force= mass x acceleration.
What is weight?
The measure of the pull of gravity on an object.
What is the gravitational field strength on earth?
10N/kg.
What is the equation for weight?
Weight= mass x gravitational field strength.
How does an object reach terminal velocity?
When an object first falls through the atmosphere, the only force acting on it is its own weight which accelerates it towards earth. As it gains speed, air resistance begins to act in the opposite direction, reducing the resultant force. Eventually the weight and the air resistance become equal, meaning the resultant force is zero. The object will now fall at a constant velocity, terminal velocity.
Name three vector quantities.
Displacement
Velocity
Force
