Science - Physics (Mechanics) Flashcards
displacement
distance than an object is from some starting point
how is motion described?
displacement, velocity, acceleration
equation for speed
speed = distance traveled/time
velocity
speed in a given direction (speed and direction)
acceleration
the rate of change in velocity
deceleration
negative acceleration or decrease in velocity - can cause change in direction
acceleration equation
acceleration = final velocity - original velocity / time
what can be described using vectors
velocity and acceleration (they both have magnitude and direction)
equation for momentum
momentum = mass x velocity
what is the main law of classical physics that states that the total momentum of an isolated system is always constant
conservation of momentum
what is newton’s first law
law of inertia
object in motion stays in motion..rest
inertia
property of matter that resists any change in motion
what is newtons second law
force = mass x acceleration (f=ma)
The newton (N) unit
unit that represents a force that accelerates a mass of 1 kg, 1 m per second
force of attraction between all objects in the universe
gravity
density equation
density = mass/vol
Torque
perpendicular force times the lever arm
lever arm
distance from the axis of rotation to the point where the force is exerted
the farther the force from the axis of rotation,
the easier it is to rotate the object and the more torque is produced
newtons third law
for every action there is, there is an equal and opposite reaction
energy
ability to do work
kinetic energy
energy associated with motion
equation for kinetic energy
kinetic energy = 1/2 (mass x velocity)^2
potential energy
energy stored in a body because of position
the product of the force applied to an object and the distance through which the force is applied
work
equation for work
work = force x distance
unit of energy equal to the work done by a force of 1 newton acting over a distance of 1 meter
joule
power
rate at which work is done
equation for power
power =
force x distance / time = work / time
what is the device that makes work easier by changing the force or the direction of an applied force
machine
efficiency
work done / energy used to power the machine
or
work input : work output
what are the 6 simple machines
inclined plane wedge screw lever pulley wheel and axle
what is a compound machine
combo of two or more simple machines
inclined plane
slanted surface used to raise an object
wedge
moving inclined plane
screw
inclined plane wrapped around a cylinder
lever
free to move around a fulcrum when force is applied
pulley
chain or rope wrapped around a wheel
wheel and axle
lever than rotates in a circle
