forces and motion Flashcards
explain with an example a scalar quantity
a scalar quantity is a magnitude
it can be described fully with a single numerical value
eg:
- distance
- speed
- time
- mass
- energy
explain with an example a vector quantity
a vector quantity has both a magnitude and a direction
eg:
- force
- velocity
- displacement
- momentum
which property of a distance time graph can be used to calculate speed
gradient (slope)
what is meant by acceleration ?
give its units
acceleration is the change in velocity per unit of time
m/s SQUARED
name two types of forces that always opposes motion
- friction
- air resistance (drag)
which type of force holds planets around the sun?
which type of force holds electrons around a nucleus?
gravitational force
electrostatic force
state the ways that a force can affect the object it is applied on
it can change the shape of the object - extension or compression
it can change the speed of the object
it can change the direction the object is moving
state the factors that can affect the stopping distance of a car
- reaction time
- initial speed
- road conditions
- tire conditions
- weather conditions
- drivers conditions
- mass of the car
state 2 factors that affect the air resistance acting on a falling object
- surface area
- speed
describe how a falling object reaches terminal velocity
at first the object falls under the effect of its weight accelerating with gravity
as its accelerating the air resistance opposing the motion increases
therefore resultant force acting on the object decreases and since F=ma acceleration decreases
when air resistance becomes equal to weight, the forces are balanced so resultant force is 0 and acceleration is 0 and object reaches terminal velocity
what is Hooke’s law?
extension is directly proportional with the force applied
explain the difference between elastic and plastic behavior
elastic behaviour - object recovers its original shape when the forces causing the extension are removed
plastic behaviour - there is a permanent deformation to the shape of the object when forces are removed
force
push or a pull
gravity
the force of attraction between objects that is due to their masses. It can affect the position of an object or the direction of its motion
friction
a force that opposes motion between two surfaces producing thermal energy
net force
the force that results from combining all the forces exerted on an object
what is the unit used to express force?
newton
velocity
the speed of an object in a particular direction
work?
when a force causes an object to move in the direction of the force
balanced force
a net force of zero
friction
a force that opposes the motion of one object moving past another
unbalanced force
forces that don’t cancel each other out when acting together on a single object
