03 Dynamics Flashcards
What are the 4 forces in nature?
-strong nuclear force
-weak nuclear force
-electromagnetic force
‐gravitational force
Put the 4 forces in nature in order from strongest to weakest?
strongest
Strong nuclear force
Weak nuclear force
Electromagnetic force
Gravitational force
Weakest
What does strong nuclear force (SNF) do?
Binds the nucleus
What does Weak nuclear force do?
Changes quark flavour
What does Electromagnetic force do?
Force binds atoms
What does gravitational force do?
Binds the solar system
Which of the forces in nature prevents the nuclei from collapsing?
Strong nuclear force
Which of the forces in nature binds neutrons together in the nucleus?
Strong nuclear force
Which of the forces in nature binds protons together in the nucleus?
Strong nuclear force
Which of the forces in nature keeps electrons orbiting the nucleus?
Electromagnetic force
Which of the forces in nature causes the normal contact force?
Electromagnetic force
Which of the forces in nature causes drag?
Electromagnetic force
Which of the forces in nature causes air resistance?
Electromagnetic force
Which of the forces in nature causes beta radiation?
Weak nuclear force
Which of the forces in nature red-giant stars to collapse?
Gravitational force
Which of the forces in nature changes quark flavour?
Weak nuclear force
Which of the forces of nature keeps the earth orbiting the sun?
Gravitational force
What is force measured in?
Newton’s (N)
What is the definition of a Newton?
A force of one Newton gives a mass of 1 kg and an acceleration of 1 m s‐²
What is weight equal to?
Weight=force of gravity=mg
What is the definition of gravitational field strength?
The force due to gravity on a mass of 1 kilogram.
What are the units for gravitational field strength?
m s‐²
N kg‐¹
What is mg?
Force of gravity
How do you lable an objects weight on a diagram?
With a downward arrow from the centre of mass labelled ‘mg’.
In which direction does friction happen?
In the opposite direction to the motion of the object.
When does friction decrease?
When the 2 surfaces are made smoother and the weight of the object decreases.
When does friction increase?
When the 2 surfaces are made rougher and the weight of the object increases.
What are frictional forces acting on an object moving through a gas or liquid also known as?
Fluid friction, drag and air resistance.
What does normal mean?
Perpendicular
At what angle does the normal contact force act?
At 90° (perpendicular) to the surfaces in contact.
What is normal contact force?
A force acting perpendicular to a surface.
What type of diagram shows the forces acting on a car?
A free body diagram
What is the resultant force?
The overall or net effect of all the forces of an object.
What does newton’s 1st law of motion state?
An object remains at rest or continues with constant velocity unless acted upon by a resultant force.
If opposite arrows on a free body diagram are the same length how do you describe them?
Equal and opposite.
In a free body diagram if the arrows are equal and opposite, what is the resultant force?
0N
If the resultant force is 0N what is concluded about the speed?
It is constant / no acceleration
What does newton’s 2nd law of motion state?
An objects acceleration is directly proportional to the resultant force acting on the object and inversely proportional to its mass (f = ma)
What does newton’s 3rd law state?
If body A exerts a force on a body B then body B exerts and equal but opposite force on body A.
What is the criteria for Newtons 3rd law forces?
- Be equal in magnitude
- Act along the same line of action
- Be forces of the same kind
- Act in opposite directions.
What is terminal velocity?
The maximum velocity achieved when there is no resultant force acting on a falling body
