Physics- Resultant Forces and Terminal Velocity Flashcards
If more than one force acts on an object their overall effect can be replaced by a single force known as….
the resultant force
Balanced Forces- What can be said about the size of the forces on a stationary object?
They are equal in size and are balanced.
When you discuss ‘fractionless’ motion for an object which had previously been given a push (eg a bit like an ice hockey puck moving along after being hit), the resultant (overall) horizontal force acting is..
almost 0
The motion this seemed to produce was one of a….
onstant speed in a straight line.
Forces unbalanced - resultant force is non-zero: The object….
accelerates or decelerates.
Forces balanced- resultant force is zero: The object….
remains at rest or continues to move with a steady speed if it is already moving.
A resultant force causes…
acceleration or deceleration.
The object will accelerate if the resultant force acts with the motion, but it will decelerate if the resultant force acts….
against the motion
If the resultant force is zero this means that the acceleration of the object is zero and this therefore means that the object moves at….
a constant speed in a constant direction.
The acceleration is……… ……….to the resultant force when the mass of the object is constant.
directly proportional
The acceleration is ……….. …………… to the mass when the resultant force is constant.
inversely proportional
Resultant force = mass x ……
acceleration
Newton’s third law: ‘action and reaction are equal but ………’
opposite
A falling object accelerates because a resultant force acts on it. The resultant force is due to the…
gravitational pull between the object and the Earth.
We call this force acting on the object its …
weight
The weight of an object is proportional to the…
mass of the object.
How many newtons of weight act on each kg of mass?
10N/kg
……. = mass x gravitational field strength
weight
Parachutists make use of air resistance (drag). Drag is a ………. ……. acting on something moving through a gas or liquid (both of these are classified as fluids).
friction force
The faster an object moves through a gas or liquid, the ……. the drag.
greater
Any object falling through a fluid is affected by drag (fluid friction). The size of the drag depends on what factors?
The speed of the object through the fluid
the size of the object
the shape of the object
Why does drag increase the faster you move though a liquid or gas?
great effect of the rubbing of molecules
