Physics Paper 1 Notes
Physics Basics
Vector Quantities
Quantities that have both a Magnitude [size] and a Direction.
Some vector quantities:
Forces
o Measured in Newtons [N]:
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 )
𝒎𝒂𝒔𝒔 𝑿 𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔)
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
Weight is the force that a body experiences due to its mass and the size of the gravitational
field that it is in.
It is measured in Newtons [N] using a Newtonmeter.
The weight of a body on the surface of the Earth acts inwards towards the Earth’s centre.
On Earth, the gravitational field strength has a value of about 9.8 Newtons per kilogram
(N/kg), which is often rounded to 10 (N/kg).
𝑾𝒆𝒊𝒈𝒉𝒕 (𝑵) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒈𝒓𝒂𝒗𝒊𝒕𝒂𝒕𝒊𝒐𝒏𝒂𝒍 𝒇𝒊𝒆𝒍𝒅 𝒔𝒕𝒓𝒆𝒏𝒈𝒕𝒉 (𝑵/ 𝒌𝒈)
The gravitational field strength of a body such as a planet depends on:
1. The mass of the body.
2. The radius of the body.
o When a body has a large mass and a small radius, it will have a large gravitational
field strength.
o The units for G.F.S. are Newtons per kilogram [N/kg] or m/𝒔𝟐 .
Velocity
o Speed in a particular direction [or the rate of change of displacement].
o 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔) = 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 ) 𝑿 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 (𝒔)
o (𝒇𝒊𝒏𝒂𝒍 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚)𝟐 − (𝒊𝒏𝒊𝒕𝒊𝒂𝒍 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚)𝟐 = 𝟐 𝑿 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 𝑿 𝒅𝒊𝒔𝒕𝒂𝒏𝒄𝒆
Acceleration
o The change in velocity over time.
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔)
o 𝑨𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 ) =
𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 (𝒔)
Momentum
o How hard it is to stop an object moving. It is a combination of mass and velocity.
o When two objects collide, the total momentum of both is the same before and after, as long as there
are no external forces acting. This is known as the conservation of momentum.
o If two objects are moving in opposite directions, we give the momentum of one a positive sign and the
momentum of the other a negative sign.
o 𝑴𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔)
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔) 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 (𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎( 𝒎/𝒔) )
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
OR 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
, Displacement
o The distance covered in a straight line [as the crow flies].
o The displacement at the end of a journey is usually less than the distance travelled because of bends
and turns in the road.
Scalar Quantities
Quantities that have a Magnitude [size] only.
Some scalar quantities:
Mass
o The amount of matter contained within a three-dimensional space.
o Measured in kg.
o The mass of a body isn’t affected by the size of the gravitational field that it is in.
Inertial mass
o A measure of how difficult it is to change the velocity of an object.
Speed
o The speed of an object tells you how far it moves in a certain time.
𝒅𝒊𝒔𝒕𝒂𝒏𝒄𝒆
o 𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝑺𝒑𝒆𝒆𝒅 = 𝒕𝒊𝒎𝒆
Distance
o The amount of ground an object has covered.
Energy
o The power or capacity to do work.
o Measured in joules [J].
Time
, Graphs
Velocity / time graphs:
Velocity/time graphs show how the velocity of a vehicle changes with time.
You can also workout acceleration and distance travel from the graph.
Physics Basics
Vector Quantities
Quantities that have both a Magnitude [size] and a Direction.
Some vector quantities:
Forces
o Measured in Newtons [N]:
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 )
𝒎𝒂𝒔𝒔 𝑿 𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔)
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
Weight is the force that a body experiences due to its mass and the size of the gravitational
field that it is in.
It is measured in Newtons [N] using a Newtonmeter.
The weight of a body on the surface of the Earth acts inwards towards the Earth’s centre.
On Earth, the gravitational field strength has a value of about 9.8 Newtons per kilogram
(N/kg), which is often rounded to 10 (N/kg).
𝑾𝒆𝒊𝒈𝒉𝒕 (𝑵) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒈𝒓𝒂𝒗𝒊𝒕𝒂𝒕𝒊𝒐𝒏𝒂𝒍 𝒇𝒊𝒆𝒍𝒅 𝒔𝒕𝒓𝒆𝒏𝒈𝒕𝒉 (𝑵/ 𝒌𝒈)
The gravitational field strength of a body such as a planet depends on:
1. The mass of the body.
2. The radius of the body.
o When a body has a large mass and a small radius, it will have a large gravitational
field strength.
o The units for G.F.S. are Newtons per kilogram [N/kg] or m/𝒔𝟐 .
Velocity
o Speed in a particular direction [or the rate of change of displacement].
o 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔) = 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 ) 𝑿 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 (𝒔)
o (𝒇𝒊𝒏𝒂𝒍 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚)𝟐 − (𝒊𝒏𝒊𝒕𝒊𝒂𝒍 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚)𝟐 = 𝟐 𝑿 𝒂𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 𝑿 𝒅𝒊𝒔𝒕𝒂𝒏𝒄𝒆
Acceleration
o The change in velocity over time.
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔)
o 𝑨𝒄𝒄𝒆𝒍𝒆𝒓𝒂𝒕𝒊𝒐𝒏 (𝒎/𝒔𝟐 ) =
𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 (𝒔)
Momentum
o How hard it is to stop an object moving. It is a combination of mass and velocity.
o When two objects collide, the total momentum of both is the same before and after, as long as there
are no external forces acting. This is known as the conservation of momentum.
o If two objects are moving in opposite directions, we give the momentum of one a positive sign and the
momentum of the other a negative sign.
o 𝑴𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔) = 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 𝒗𝒆𝒍𝒐𝒄𝒊𝒕𝒚 (𝒎/𝒔)
𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎 (𝒌𝒈 𝒎/𝒔) 𝒎𝒂𝒔𝒔 (𝒌𝒈) 𝑿 (𝒄𝒉𝒂𝒏𝒈𝒆 𝒊𝒏 𝒎𝒐𝒎𝒆𝒏𝒕𝒖𝒎( 𝒎/𝒔) )
o 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
OR 𝑭𝒐𝒓𝒄𝒆 (𝑵) = 𝒕𝒊𝒎𝒆 𝒕𝒂𝒌𝒆𝒏 𝒇𝒐𝒓 𝒕𝒉𝒆 𝒄𝒉𝒂𝒏𝒈𝒆 (𝑺)
, Displacement
o The distance covered in a straight line [as the crow flies].
o The displacement at the end of a journey is usually less than the distance travelled because of bends
and turns in the road.
Scalar Quantities
Quantities that have a Magnitude [size] only.
Some scalar quantities:
Mass
o The amount of matter contained within a three-dimensional space.
o Measured in kg.
o The mass of a body isn’t affected by the size of the gravitational field that it is in.
Inertial mass
o A measure of how difficult it is to change the velocity of an object.
Speed
o The speed of an object tells you how far it moves in a certain time.
𝒅𝒊𝒔𝒕𝒂𝒏𝒄𝒆
o 𝑨𝒗𝒆𝒓𝒂𝒈𝒆 𝑺𝒑𝒆𝒆𝒅 = 𝒕𝒊𝒎𝒆
Distance
o The amount of ground an object has covered.
Energy
o The power or capacity to do work.
o Measured in joules [J].
Time
, Graphs
Velocity / time graphs:
Velocity/time graphs show how the velocity of a vehicle changes with time.
You can also workout acceleration and distance travel from the graph.
