Forces Flashcards
(38 cards)
What is a vector quantity? Give examples of it.
Vector quantities have magnitude and direction Force Velocity Displacement Acceleration
What is a scalar quantity? Give an example of it.
Scalar quantities only have magnitude and no direction Speed Distance Time Mass Temp
What is a non contact force and give examples of it?
It is where two objects do not need to be touching for the force to act.
Gravitational force
Magnetic force
Electrostatic force
What is a contact force and give examples of it?
When two objects have to be touching for a force to act,
Friction
Air resistance
Tension in normal ropes
What is weight measured in?
Weight is a force measured in Newtons
What is mass measured in?
Mass is mot a force and is measured in kilograms
Are weight and mass directly proportional?
Yes
What is the equation for weight?
Weight = Mass (kg) x Gravitational Field Strength (N/KG]
What is the work done equation?
Work done = force x distance
What is meant by an object being equilibrium?
If all of the forces acting on an object combine to give a resultant force of zero, the object is equilibrium.
What is the equation involving spring constant and extension?
Force = spring constant x extension
What is the equation for moment of force?
Moment of force = Force x distance
What does pressure equal?
It has two equations name them both.
Pressure = Force/area
Pressure = hpg
Height x gravitational x density of liquid
Why does an object float?
An object floats if its weight = upthrust
The higher you go, what happens to the atmospheric pressure and why?
Pressure decreases with height this is because as the altitude increases, the atmosphere gets less dense, so there are fewer molecules that are able to collide with the surface.
What does speed equal?
Speed = distance x time
What is the equation of acceleration?
Acceleration = change in velocity/time
What is uniform acceleration?
Uniform acceleration means a constant acceleration
What is the uniform equation?
Final velocity - initial velocity = 2 x acceleration x distance
Explain why a ball falling from the top of a tall building reaches terminal velocity?
1) when the ball falls, it accelerates due to the force of gravity.
2) air resistance also acts on the ball, in the opposite direction to the force due to gravity
3) as ball speeds up, air resistance increases until accelerating force and air resistance are balance
4) the object cant go any faster this is terminal velocity
What does friction do?
They slow things down
When the speed increases what happens to the drag?
Drag increases as well
What does resultant force equal?
Resultant force = mass x acceleration
What is inertia?
Inertia is the tendency for motion to remain unchanged
