Mechanics - Unit 1: Vectors in Two Dimensions
Monday, August 31, 2020 7:30 PM
Rx → : Horizontal Vectors
Ry ↑: Vertical Vectors
Longer the line Stronger the force
Physical Quantity → Something you can measure and put measurement to
+ and - show direction (assign which is + and which is -)
Calculations:
• Magnitude → use pythagoras
• Direction → use trig ratios
Fx: cosƟ =
Fx = FcosƟ
Fy: sinƟ =
Fy = FsinƟ
Generalized Answer: Resultant equals ____N at an angle of ____° from the vertical/horizontal to the right/left.
Mechanics Page 1
, Mechanics - Unit 2: Newton's Laws
Wednesday, September 2, 2020 9:16 PM
Definitions
Weight (Fg) → the force with which an object is attracted to the earth
Parallel Component (F‖)→ the force which causes the object to slide down the slope
Perpendicular Component (FꞱ)→ the force with which the object presses onto surface
Tension→ when pulling forces are applied to the end of a solid
Normal Force (FN)→ the force exerted by a surface on an object which is in contact with the surface
Frictional Force (Ff/f)→ the force that opposes the motion of an object and acts parallel to the surface with which the
object is in contact.
Static friction (fs)→ frictional force when object not moving
Kinetic/Dynamic friction (fk)→ frictional force when object is in motion
Newton's First Law Of Motion→ states that an object remains at rest or moves at a constant speed in a straight line
unless acted upon by a net (resultant) force
Inertia→ that property of matter which tends to make it continue in a state of rest or of uniform motion in a straight line
Newton's Second Law Of Motion→ states that if a net (resultant) force acts on an object, the object will accelerate in
the direction of that force. The acceleration is directly proportional to the net force and inversely proportional to the
mass of the object.
Newton (N)→ as the force which is required to produce an acceleration of 1 m.s⁻² on a body of mass 1 kg.
Newton's Third Law of Motion→ states that when object A exerts a force on object B, object B simultaneously exerts an
oppositely directed force of equal magnitude on object A.
Force Field→ is a region in which an object will experience a force
Gravitational Force→ is a region in which any mass will experience a force which is gravitational in nature.
Gravitational Field Strength→ at a point in the field is the force which a 1 kg mass experiences at that point.
Newton's Law of Universal Gravitation→ states that every body attracts every other body in the universe with a force
that is directly proportional to the product of the masses and inversely proportional to the square of the distance
between their centres.
Types of Forces
All forces are vectors have magnitude and direction.
SI Unit: Newton.
Forces:
g = acceleration due to gravity (9,8 m.s⁻²)
• Weight
m = mass of object (kg)
Fg = mg
○ Object on Horizontal surface → object exerts a force on surface which is equal to the weight of the object.
○ Object rests on a slope → the weight can be broken into two components which are at right angles to each
other, one acting ǁ to the surface and the other Ʇ to the surface.
○ Always height of triangle cosƟ =
FꞱ = Fg cosƟ
sinƟ =
Fǁ = Fg sinƟ
• Tension
• Normal Force
○ Always Ʇ to surface
○ Horizontal surface → Fg = FN in magnitude (provided no other vertical forces acting on object)
Inclined surface → FN = Ʇ component of Fg (FꞱg) (provided no other vertical forces acting on object)
Mechanics Page 2
Monday, August 31, 2020 7:30 PM
Rx → : Horizontal Vectors
Ry ↑: Vertical Vectors
Longer the line Stronger the force
Physical Quantity → Something you can measure and put measurement to
+ and - show direction (assign which is + and which is -)
Calculations:
• Magnitude → use pythagoras
• Direction → use trig ratios
Fx: cosƟ =
Fx = FcosƟ
Fy: sinƟ =
Fy = FsinƟ
Generalized Answer: Resultant equals ____N at an angle of ____° from the vertical/horizontal to the right/left.
Mechanics Page 1
, Mechanics - Unit 2: Newton's Laws
Wednesday, September 2, 2020 9:16 PM
Definitions
Weight (Fg) → the force with which an object is attracted to the earth
Parallel Component (F‖)→ the force which causes the object to slide down the slope
Perpendicular Component (FꞱ)→ the force with which the object presses onto surface
Tension→ when pulling forces are applied to the end of a solid
Normal Force (FN)→ the force exerted by a surface on an object which is in contact with the surface
Frictional Force (Ff/f)→ the force that opposes the motion of an object and acts parallel to the surface with which the
object is in contact.
Static friction (fs)→ frictional force when object not moving
Kinetic/Dynamic friction (fk)→ frictional force when object is in motion
Newton's First Law Of Motion→ states that an object remains at rest or moves at a constant speed in a straight line
unless acted upon by a net (resultant) force
Inertia→ that property of matter which tends to make it continue in a state of rest or of uniform motion in a straight line
Newton's Second Law Of Motion→ states that if a net (resultant) force acts on an object, the object will accelerate in
the direction of that force. The acceleration is directly proportional to the net force and inversely proportional to the
mass of the object.
Newton (N)→ as the force which is required to produce an acceleration of 1 m.s⁻² on a body of mass 1 kg.
Newton's Third Law of Motion→ states that when object A exerts a force on object B, object B simultaneously exerts an
oppositely directed force of equal magnitude on object A.
Force Field→ is a region in which an object will experience a force
Gravitational Force→ is a region in which any mass will experience a force which is gravitational in nature.
Gravitational Field Strength→ at a point in the field is the force which a 1 kg mass experiences at that point.
Newton's Law of Universal Gravitation→ states that every body attracts every other body in the universe with a force
that is directly proportional to the product of the masses and inversely proportional to the square of the distance
between their centres.
Types of Forces
All forces are vectors have magnitude and direction.
SI Unit: Newton.
Forces:
g = acceleration due to gravity (9,8 m.s⁻²)
• Weight
m = mass of object (kg)
Fg = mg
○ Object on Horizontal surface → object exerts a force on surface which is equal to the weight of the object.
○ Object rests on a slope → the weight can be broken into two components which are at right angles to each
other, one acting ǁ to the surface and the other Ʇ to the surface.
○ Always height of triangle cosƟ =
FꞱ = Fg cosƟ
sinƟ =
Fǁ = Fg sinƟ
• Tension
• Normal Force
○ Always Ʇ to surface
○ Horizontal surface → Fg = FN in magnitude (provided no other vertical forces acting on object)
Inclined surface → FN = Ʇ component of Fg (FꞱg) (provided no other vertical forces acting on object)
Mechanics Page 2
