Floating
Particles
Thermal Energy
Mechanics
Pot Luck
100
the change of velocity in metres per second (m/s) in 1 second (s) - the unit is m/s/s or m/s² (metres per second squared)
acceleration
100
the temperature at which the vapor pressure of a liquid is equal to the pressure of the atmosphere on the liquid, equal to 100°C (212°F, 373°K) for water at sea level
boiling point
100
Relating to a temperature scale on which the freezing point of water is 0° and the boiling point of water is 100° under normal atmospheric pressure.
Celsius
100
the rate of change (∆) of velocity (v) with respect to time a= V₁ - V₀ / t =∆v/t
acceleration
100
Quantities fully described by magnitude alone are ____
scalars
200
any flat, curved, or irregular expanse of a surface. Unit m² (square metres), cm² (square centimetres)
area
200
an artificial, stone like material used for various structural purposes, made by mixing cement and various aggregates, as sand, pebbles, gravel, or shale, with water and allowing the mixture to harden
concrete
200
the transfer of heat between two parts of a stationary system, caused by a temperature difference between the parts.
conduction
200
an external cause for acceleration in a physical system = m x a
force
200
If an object is at rest, then there are no forces acting upon the object. True or False?
FALSE
300
mass per unit volume - in kg/m³ . Formula mass/volume. d=m/v.
density
300
become smaller; shrink
contract
300
the transfer of heat by the circulation or movement of the heated parts of a liquid or gas.
convection
300
an attractive force between particles with mass
gravity
300
A force is required to keep an object moving in a given direction.True or False?
FALSE
400
one hundred pascals
hectopascal
400
temperature at which a liquid changes to a solid
freezing point
400
mass per unit volume. e.g. kg/m3
density
400
the SI unit of force, equal to the force that produces an acceleration of one meter per second per second on a mass of one kilogram. (1kg/m/s^2 =1 ____)
newton
400
Why do objects float in liquids denser than themselves?
If an object were completely immersed in a liquid denser than it, the resulting buoyant force would exceed the weight of the object. This is because the weight of the liquid displaced by the object is greater than the weight of the object (since the liquid is denser). As a result, the object cannot remain completely submerged and it floats. The scientific name for this phenomenon is Archimedes Principle.
500
the property of a fluid to exert an upward force (upthrust) on a body that is wholly or partly submerged in it
buoyancy
500
the energy of a body or a system with respect to the motion of the body or of the particles in the system
kinetic energy
500
the capacity of a body or system to do work
energy
500
A body remains at rest or in motion with a constant velocity unless acted upon by an external force.
Newton's First Law of Motion
500
Do heavier objects fall more slowly than lighter objects?
No. If an object is heavier the force of gravity is greater, but since it has greater mass the acceleration is the same, so it moves at the same speed (if we neglect air resistance). If we look at Newton's second law, F = ma. The force of gravity is F = mg, where m is the mass of the object and g is the acceleration due to gravity. Equating, we have mg = ma. Therefore, a = g. If there was no air resistance, a feather would fall at the same speed as an apple.
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