Physics Chapter 5 : Forces

Created by

Anjola Somefun

Cards (51)

What is a force ?
A force is a push or pull that acts on an object as a result of that objects interaction with the surroundings.
What are the two types of forces called ?
Contact and non-contact
What is a non-contact force ?
A non-contact force can be exerted without objects physically touching
Name Non-Contact Forces
Electrostatic Force, Magnetic Force, Gravitational Force
What is a Contact Force ?
A contact force can only be exerted when objects are physically touching
Name Contact Forces
Tension, Friction, Air Resistance, Normal Contact Force
Force is measured in Newtons and has both magnitude and direction and therefore is a vector quantity
What is a scalar quantity ?
Scalar quantities have magnitude only
What is a vector quantity ?
A vector quantity has both magnitude and direction.
Name Scalar Quantities
temperature, distance, speed
Name Vector Quantities
displacement (15KM EAST), weight, velocity
What is resultant force ?
The overall force acting on an object, taking into account all the different forces acting on it
What properties affect resultant force ?
speed and direction
What is it called when all forces acting on an object are equal ?
Equilibrium
What is elastic deformation ?
if an object does return to its original shape after the force is removed
What is inelastic deformation ?
If the object does not return back to its normal shape after the force is removed
What is extension ?
increase in length of a spring when it's stretched
What is spring constant ?
measure of how many newtons of a force would require to stretch (or compress) the object by 1 metre.
The higher the spring constant the more stiff the spring is
The lower the spring constant the less stiff the spring is
What is Hooke's Law
Force= spring constant X extension
What is moment ?
The turning effect of a force
What is a lever ?
Levers work by transmitting the turning effect of a force
When applying force to an object what does it do ?
Stretch, Compress or Bend
What are the factors affecting the pressure exerted in a liquid ?
depth- the greater the depth, more pressure exerted
density- more dense liquids exert greater pressure
the gravitational field strength-this is 9.8 N/m on earth
What is upthrust ?
The pressure on the bottom of the object being greater than the pressure on the top of the object
Atmospheric pressure is lower at higher elevation
What is atmospheric pressure ?
The total force of all air particles constantly colliding with everything from all sides.
What is the difference between speed and velocity ?
Speed is a scalar quantity that measures how fast an object is moving and has magnitude only. Whereas velocity is the speed of an object in a given direction and is a vector quantity that has both magnitude and direction.
What is acceleration ? 
The rate of change of velocity.
Constant acceleration is also known as uniform acceleration
What is terminal velocity ? 
Maximum speed reached by a falling object.
What factors affect terminal velocity ?
Surface area, weight, and air resistance.
How do you know terminal velocity is reached ?
Terminal velocity is reached when the resultant force is zero and the weight has the same magnitude as air resistance.
As the velocity of the falling object increases, the air resistance increases.
If the object has not reached terminal velocity this means the object is still accelerating
What does the size of air resistance depend on ?
Surface area and velocity
What is Newtons First Law ?
A resultant force is needed to change motion ( start moving, speed up, slow down )
What is Newtons Second Law ?
Acceleration is directly proportional to the resultant force. A resultant force will cause an object to accelerate in the direction of the force.
What is Newtons Second Law (Equation) ?
F = ma