PHY101 - Physics Flashcards
What type of quantity is displacement?
It’s a vector quantity.
Physics, what is it?
It’s the study of matter & energy in our surroundings.
What is mechanics?
The study of the motion of objects and the force & energy
What are the branches of mechanics?
- Kinematics
- Dynamics
What is kinematics?
It’s the description of how objects move
What is dynamics?
It is the study of forces on objects and why objects move as they do so.
What is translational motion?
The motion of objects that go straight without rotating
What’s a particle?
A mathematical point with no size, used as assumptions in our calculations
What do we always associate the motion of a particle within Physics?
A frame of reference e.g the earth, a bus, a train etc.
How do we represent the motion of an object?
Using a Cartesian Coordinate system
Origin of cartesian coordinate has which coordinates please?
x = 0 & y= 0
What is the position of the body?
A point where the object is at in the cartesian coordinate
What is displacement?
It is how far is an object from the starting point
What is displacement?
The Change in position of the object
What type of quantity is displacement/
A vector quantity, since it has both, magnitude & direction.
Average speed, what is it?
It’s the total distance travelled divided by the amount of time it took to reach that path
What’s the difference btn Speed & velocity?
Speed is simply a unit, while Velocity is speed with magnitude & direction
What is average velocity?
It’s the speed defined in terms of displacement over time taken, instead of distance over time
What does the displacement & average velocity being negative mean?
It means that an object s moving to the left of the Cartesian coordinate. Since the Cartesian coordinate is our reference frame.
What’s instantenous velocity?
It’s the velocity at any instant in time. Or Average velocity over an infitesimal short time interval
When is the instantenous velocity the same as the average velocity?
When a particle is moving at a uniform/constant velocity
What’s instantenous velocity?
It’s the velocity at any instant in time. Or Average velocity over an infinitesimal short time interval
State of acceleration, what is it?
A state where an object’s velocity is changing
What is average acceleration?
It’s the change in velocity divided by a change in time taken to make this change.
What is deceleration?
It’s an act of where an object is slowing down.
What’s one example of uniform accelerated motion?
Motion of a free falling object near the earth surface
State Gallilleo Gallillei’s principle of free fall objects:
“All objects fall with the same acceleration in the absence of air or any other resistance”
What’s one example of uniform accelerated motion?
The motion of a free-falling object near the earth’s surface
As the object falls down to the ground, & with the air resistance, will the velocity just keep increasing infinitely?
No, it will reach a certain velocity we call Terminal velocity.
What are projectiles?
Are objects thrown near the earth’s surface, following a curved path, with 2 dimensions.
What’s a VECTOR quantity?
An object with both magnitude & direction.
What are SCALAR quantities?
They are objects which aren’t VECTORS like mass, length & time.
What are the COMPONENTS of vectors?
They are VECTORS DERIVED from original VECTORS.
What’s the Resolving of vectors?
Is the process of finding the Components of the Original Vector.
What is a UNIT VECTOR?
It means a vector to have a MAGNITUDE EQUAL TO 1
What is a Displacement vector?
It’s the Vector representing the change in position.
What is Projectile motion?
It’s the motion of objects in 2-Dimensions thrown at an angle near the Earth’s surface.
What is dynamics?
It is the subject which deals with force & motion
Force
Is the push or pull experienced by an object
What are Contact forces?
They are the forces in which 2 the force itself is in contact with an object. Example you pulling a cart
What is an example of a non-contact force?
The force of gravity
What is weight?
Is the amount of force of gravity acting on an object
What is a Spring Scale?
An instrument to measure weight
State NEWTON’S FIRST LAW OF MOTION:
Every object continues in its state of rest, or of uniform velocity in a straight
line, as long as no net force acts on it.
What is Newton’s first Law referred to?
It’s referred to The Law of Inertia
What is inertia?
The tendency of an object to maintain its state of rest or of uniform velocity in a straight line.
What are inertial reference frames?
They are the reference frames which Newton’s laws hold true.
What is mass?
Measure of inertia of an object
What is mass?
The measure of inertia of an object
Newton’s Second Law:
The acceleration of an object is directly proportional to the net force acting
on it, and is inversely proportional to the object’s mass. The direction of the acceleration is in the direction of the net force acting on the object.
Newton’s Third Law:
Whenever one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first.
Newton’s Second Law:
The acceleration of an object is directly proportional to the net force acting
on it, and is inversely proportional to the object’s mass. The direction of the acceleration is in the direction of the net force acting on the object.
What’s the NORMAL FORCE?
When the Contact force of the Surface is acting perpendicular to the common surface.
What’s the NORMAL FORCE?
When the Contact force of the Surface is acting perpendicular to the common surface.
What’s the NORMAL FORCE?
When the Contact force of the Surface is acting perpendicular to the common surface.
How is the Direction of action of the Normal Force?
It acts:
- Vertical = on a horizontal surface
- Horizontal = on a vertical surface
- Perpendicular on an inclined surface
What does the Negative Normal force exerted on an object mean?
It means that the Object is not receiving any normal force from the plane. .A.K.A = It has been fully lifted off.
What’s the NET FORCE?
It’s the Vector sum of all forces acting on a system in a certain direction.
What’s a FREE BODY DIAGRAM?
It’s a representation of Forces acting on an Object when working out a Force-related Question.
What is a SYSTEM?
A system is a combination of two or more objects we consider to Study.
Energy & momentum are…?
Conserved! (They remain constant)
What is Kinetic Energy?
Is the energy at motion
State the WORK-ENERGY Principle:
The Net work done sis equal to the difference in Kinetic Energy of the object
