Forces Flashcards
What can a force do
Change the state of motion of an object, speed it up, slow it down, stop it from moving, hold it in place, change direction
What does a force involve
Physical contact between objects
What are the two main types of forces
Contact forces, action at a distance forces
What is a contact force
Types of forces in which the two interacting objects are physically contacting eachother
What is action at a distance forces
Two interacting objects , not in physical contact with eachother . Able to exert a push or pull, based on physical separation
What is gravity
Between any two objects with mass
What is electrostatic
Between positive and negative charges
What is magnetic
Between magnetic objects
What is an applied force
A force which is applied to an object by a person or another object
What is frictional force
The force exerted by a surface on an object , as the object moves across it , or makes an effort to move across it
What does friction result from
The two surfaces being pressed together closely, causing intermolecular attractive forces between molecules and different surfaces
What is tension
The force which is transmitted through a string , rope, or wire, when it is pulled tight by forces acting from each end
What is air friction
A pushing force by the air opposing the motion of the object through the air
What is a normal force
Support force exerted upon an object which is in contact with another stable object
What is gravitational force
Force of attraction between any two objects which have mass
What is the difference between mass and weight
Mass is the amount of substance present in kg
Weight is the force of the earth on us (n)
What direction does gravity always go
Downwards
How do we calculate gravity force
Mass times 9,8
What is a force defined as
A push or pull
What is the net force acting on the body?
A net force is the single force which would have the same effect as all of the forces acting together, if it were to replace all the forces acting on the body
What does vector addition mean
All forward forces positive and backward forces negative , and them add the forces
What happens when the net force is zero
The objects motion does not change . The forces are balanced and it is in equilibrium
If the forces on an object are balanced
The object is stationary , it will remain stationary
How can forces be balanced with a moving object
Carry on moving at the same speed, in the same direction, won’t speed up, slow down, or change direction
A force is not required to keep a moving book in motion…
In actuality it is a force which brings the book to rest
What happens when the net force is not zero
The forces are unbalanced and the object accelerates
How does an object accelerate
It speeds up, slows down, or changes direction
What is the equation for finding the relationship between the net force on an object and the acceleration of the object
F net = ma
What is mass measured in
Kg
What is f net
Force of newtons
What is the acceleration measured in
M.s -2 and has the same direction as the force
What is the definition of work
Work is done by a force , if the force moves an object a distance
What are the 3 conditions for work to be done on a force
The object must move ,
The force must be acting in the same direction as movement
Force must act on object during entire movement
What equation is done to find the work done by the force
W= f.x
Force x distance
What is the definition of power
Rate at which work is done
What is the calculation of power
P = w/t
Power (watts) = work ( joules) divided by time (seconds)
What are the differences between weight and mass
Mass = kg , weight = N
Mass is amount of substance present, weight is force of the earth on us
Mass has no direction, weight has force so has direction
How many weeks in a year
52
What is the triangle
P , t , work at top
What is 1 liter
1 kg
How many kj in a jule
1000
What does 200 js -1
200 watts
What’s the difference between weight and mass
Weight is the force of the earth on us. Newtons. Vector quanitity
Mass is the amount of substance present. Kg. Scalar quantity
