Motion and Forces
http://www.nuffieldfoundation.org/practical-physics/introduction-forces
* important website *
* important website *
Definitions:
Force: an action that can change the motion of an object, or deform the object, by pushing or pulling on it.
Motion: involves speed, acceleration, velocity, and time.Mass: the measure of the quantity of matter in an object
Weight: the measure of the gravitational force acting on an object
Motion: involves speed, acceleration, velocity, and time.Mass: the measure of the quantity of matter in an object
Weight: the measure of the gravitational force acting on an object
The Relationship between speed, distance, and time.
formula: v=d/Δt
v= average speed in meters/second
d= distance traveled in meters
Δt= travelling time in seconds
Ex: The average speed of a car that travels 10km/10min, what is the average speed?
v=d/Δt v=10 000m/600s v= 16.67m/s
v= average speed in meters/second
d= distance traveled in meters
Δt= travelling time in seconds
Ex: The average speed of a car that travels 10km/10min, what is the average speed?
v=d/Δt v=10 000m/600s v= 16.67m/s
The Relationship between mass and weight
Mass: the measure of the quantity of matter in an object
Weight: the measure of the gravitational force acting on an object
Formula: w=Fg=mg
w= weight in newtons
Fg= gravitational force in newtons
m= mass in kilograms
g= gravitational field intensity in newtons/kilogram
Weight: the measure of the gravitational force acting on an object
Formula: w=Fg=mg
w= weight in newtons
Fg= gravitational force in newtons
m= mass in kilograms
g= gravitational field intensity in newtons/kilogram
Types of Forces
Gravitational force: force of attraction between all objects as a result of their masses and the distance between them. Earth's gravitational force is 9.8m/s²
Electromagnetic force: is a force of attraction or repulsion between two objects with an electrical charge or with magnetic poles.
Force of Friction: is a force that prevents two objects from slipping over each other when they come into contact.
Resultant force: is the sum of all forces applied to one object simultaneously.
Effective Force: the force that changes the motion of an object and it parallel to the movement of the object.
Electromagnetic force: is a force of attraction or repulsion between two objects with an electrical charge or with magnetic poles.
Force of Friction: is a force that prevents two objects from slipping over each other when they come into contact.
Resultant force: is the sum of all forces applied to one object simultaneously.
Effective Force: the force that changes the motion of an object and it parallel to the movement of the object.
Electromagnetic force:
not all metals are magnetic (FeNiCo) Iron, nickel, cobalt
All magnets contain domains, and in a magnetic field the domains line up. The magnetic field lines come out of the North end of a magnet and go into the south, they are concentrated at the poles (north & south)
the laws of magnetism are that like poles repel and unlike poles attract.
All magnets contain domains, and in a magnetic field the domains line up. The magnetic field lines come out of the North end of a magnet and go into the south, they are concentrated at the poles (north & south)
the laws of magnetism are that like poles repel and unlike poles attract.
force of Friction
friction depends on two factors...
- the nature of surfaces in contact (the rougher the surfaces, the greater the friction)
- the intensity of the pressure of each surface on the other (the higher the pressure, the greater the friction)
- the nature of surfaces in contact (the rougher the surfaces, the greater the friction)
- the intensity of the pressure of each surface on the other (the higher the pressure, the greater the friction)
Forces measured in Newtons
1N= 1kg x 1 m/s²
A force can change the motion of an object in different ways:
- A force can give a certain velocity to a stationary object
- It can also increase the velocity of an object already in motion
- A force can reduce the velocity of a stationary object
- It can also decrease the velocity of an object already in motion
- A force can modify the trajectory of an object
A force can change the motion of an object in different ways:
- A force can give a certain velocity to a stationary object
- It can also increase the velocity of an object already in motion
- A force can reduce the velocity of a stationary object
- It can also decrease the velocity of an object already in motion
- A force can modify the trajectory of an object
Resultant Force
the resultant force is calculated in the following ways...
- the sum of two forces applied in the same direction
- the difference between two forces applied in opposite directions
- the sum of two forces applied in the same direction
- the difference between two forces applied in opposite directions
Effective Force
SOH CAH TOA
sinƟ= opposite side/hypotenuse
cosƟ= adjacent side/hypotenuse
tanƟ= opposite side/adjacent side
sinƟ= opposite side/hypotenuse
cosƟ= adjacent side/hypotenuse
tanƟ= opposite side/adjacent side
Practice worksheets for speed, time and distance
speed_distance_time_worksheet.pdf | |
File Size: | 62 kb |
File Type: |
Practice worksheets for mass and weight
a-mass_and_weight_worksheet.doc | |
File Size: | 100 kb |
File Type: | doc |
Click "electromagnetism" button for a practice sheet on electromagnetism
A video of friction on an inclined plane!