MECHANICS - DYNAMICS - MOTION Flashcards
Newtons 1st Law
An object in motion stays in motion, an object at rest stays at rest unless acted upon an outside force.
Newton’s 2nd Law
F = ma
Force = mass x acceleration
Newton’s 3rd Law
For every action, there is an opposite and equal reaction
What is a FORCE
A push or pull applied by one object and experienced by another object
What is NET FORCE
The single force that could replace all the individual forces acting on an object and produce the same effect. Forces acting in the same direction add together to determine the net force. Forces actin in opposite directions subtract to determine the net force.
what is WEIGHT
weight is the force of a planet on an object near that planet. for example: an object weighs more on the earth than the moon.
what is FORCE OF FRICTION
the force of a surface on an object
what is KINETIC FRICTION
the friction force when something is moving along the surface and acts opposite the direction of motion
what is STATIC FRICTION
the friction force between two surfaces that aren’t moving relative to one another
what is NORMAL FORCE
is also the force of a surface on an object. the normal force acts perpendicular to the surface
what is COEFFICIENT OF FRICTION
the number that tells how sticky 2 surfaces are
what is NEWTON’S 3RD LAW
says that the force of OBJECT A on OBJECT B is equal in amount and opposite in direction to the force of OBJECT B on OBJECT A
what is NEWTON’S 2ND LAW
states that an object’s acceleration is the net force it experiences divided by its mass, and is in the direction of the net force
what 2 forces can act on an object without contact
gravitational and electrical forces
what is MOMENTUM
a moving object’s momentum is its mass times its velocity. momentum is always in the direction of motion
what is IMPULSE
impulse is defined as a force multiplied by the time during which that force acts. the net impuls on an object is equal to the change in that object’s momentum
what is a SYSTEM
a system is made up of several objects that can be treated as a single thing. It’s important to define the system you are considering before you treat a set of objets as a system.
Define “Projectile”
An object in free fall.
What if an object is launched at an angle - how would you describe the vectors?
You treat the horizontal and vertical vectors separately.
In projectile motion in which launched at an angle, describe the important traits of the horizontal vector
There is NO horizontal acceleration - therefore an object would move at constant speed. Acceleration = 0
A projectile is launched at an angle - describe the vertical vector.
The vertical vector is influenced by the acceleration of gravity and is represented by - 10 m/s/s
Describe how you would setup a projectile launched at an angle word problem.
You setup 2 kinematic charts. One chart is for the horizontal component and the 2nd chart is for the vertical component.
A projectile is launched at an angle - what is the trig function to calculate the horizontal component for velocity?
v(cos Ø)
A projectile is launched at an angle - what is the trig function to calculate the vertical component for velocity?
v (sin Ø)
In the horizontal kinematic chart for projectiles, what can we assume with the horizontal variables?
The initial and final velocity is the same. Time is the same as vertical kinematic chart. Acceleration is zero.
In the vertical kinematic chart for projectiles, what can we assume with the vertical variables?
Initial velocit is v(sinØ), acceleration is -10m/s/s, and generally displacement delta x = 0 or displacement = 0
