Physics P8 9 And 10 Flashcards
(50 cards)
What is a vector ?
A vector is a quantity that has size and direction .
What is a scalar quantity ?
A scalar quantity has size but no direction
What are 5 examples of scalar quantities ?
Mass , power , energy , time and speed .
What are 5 examples of vector quantities ?
Displacement , velocity , force , weight and acceleration .
What does displacement mean ?
A measure of how far an object moves in a given direction .
What is acceleration ?
The rate of change in velocity
What is speed ?
The measurement in the increase of distance .
What is velocity ?
It is the speed of a given direction
What is mass ?
The amount of an object that is present .
What is weight ?
The force acting on an object due to gravity
What is a force ?
A force is a push or pull on an object with direction .
What is energy ?
Energy is the amount of work done without a direction .
What is power ?
The ability to do work with speed .
How can a vector be shown on paper ?
An arrow showing the direction the vector is going towards in . The size of the vector can also be shown by the size of the arrow .
What are 4 examples of a contact force ?
Air resistance
Friction
Stretching
Tension
What is the difference between a contact force and a non contact force ?
A contact force is physically touching an object to make it move . Whereas non contact forces do not require the objects to be toucning .
What is newtons third law of motion ?
When two objects interact with one another , they both exert equal and opposite force on each other.
What is friction ?
Friction is the force exerted by a surface against an object when it moves across it .
What is a resultant force ?
A resultant force is the the combined effect of multiple forces acting on a single object .
What happens when a resultant force is zero ?
The forces acting on the object are balanced
How can resultant forces be shown ?
In a free body diagram
What is the centre of mass of an object ?
The centre of mass of an object can be thought of as the point at which its mass can be thought of as being concentrated .
How can the centre of mass of a regular object be found ?
By drawing lines and where they meet is the centre of mass
What are the four steps in finding the centre of mass in an irregular object ?
- Make sure you have a retort stand , a cork pin and a plumb line .
- Then you find two points of an object or shape , then let the plumb line hang from one point and draw a line along it .
- Next hang the plumb line at the second point and draw a second line along it .
- The centre of mass will be the point at which those two lines cross .
