Forces Flashcards
What is a SCALAR QUANTITES
Only have a magnitude and no direction
What are examples of SCALAR QUANTITIES
Speed Mass Distance Time Temperature
What is a VECTOR QUANTITIES
Have a magnitude and a direction
What are 5 examples of VECTOR QUANTITIES
Force Displacement Momentum Velocity Accerleration
What is the definition of FORCE
A push or pull on an object caused by it intertracting with something.
What are the two types of forces?
Contact forces
Non-contact forces
What is the defintion of a CONTACT FORCE
Forces that occur by two or more objects touching
What is the definition of a non-contact force
Forces that occur between two or more objects that are not touching
What are 4 examples of a contact force
1) Friction
2) Tension
3) Air resistance
4) Normal contact force
What are 3 examples of non-contact forces
1) gravitaional force
2) electrostatic force
3) magnetic force
What is the definition of weight
A force that acts on an object due to gravity
What is the equation to calculate weight
W = mg
Weight(N) = mass(kg) x gravitational field strength(N/kg)
What is the definition of a free body diagram
Shows all forces acting on an isolated object (taken from the centre of mass)
What is the definition of equilibrium
When the forces acting on an object are balanced and the resultant force is zero.
What is the definition of a resultant force
A single force that can replace all the forces acting on an object and give the same effect as the original forces acting together.
How do you calculate the resultant force
Add forces pointing in the same direction together. subtract forces pointing in the opposite direction
F1 - F2 = resultant force
What is the definition of work done
When a force moves an object from one point to another, energy is transferred and work is done the object.
What is the equation of work done
W = Fs
Work done(J) = Force(N) x Distance(M)
What is the definition of distance
Distance is a scalar and it measures how far an object has moved (not including direction)
What is the definition of Displacement
Displacement is a vector that measures the distance and direction in a straight line from the starting postion to the finishing position of an object.
What is the definition of speed
Speed is a scalar that measures how fast your going with no regard to direction
What is he equation of speed
s = vt
distance travelled(m) = speed(m/s) x time(s)
What are 4 things that can affect a persons walking, running or cycling abilities
1) ability
2) age
3) distance travelled
4) type of ground
What are the average speeds for walking, running, cycling and sound
1) 1.5 m/s
2) 3 m/s
3) 6 m/s
4) 330 m/s
What is the definition of velocity
velocity is a vector and it measures speed with a certain direction
What is the defintion of acceleration
The change in velocity in a certain amount of time
What is the equation for acceleration
acceleration(m/s*2) = change in velocity (m/s) / time(s)
What is deceleration
Deceleration is negative acceleration (shows an object slowing down)
What is the acceleration of an object falling due to gravity close to Earth’s surface
roughly 9.8 m/s*2
What is the definition of inertia
The tendency of an object to continue in the same state of motion
What is Newtons first law explained
1) if zero resultant force acts on a stationary object, the object doesnt move
2) If zero resultant force acts on a moving object, it continues moving at the same velocity.
3) If a non-zero resultant force acts on an object, object accelerates or decelerates ( will change speed, direction or both)
What is the definition of Newtons first law
An object will remain at rest or travel at a constant velocity unless it is acted on by a resultant force above zero
What is the definition of Newtons second law
The acceleration of an object is directly proportional to the resultant force acting on it, and inversely proportional to its mass
What is the equation used within Newtons second law
F = ma
What is the definition of inertial mass
Measure of how hard it is to change an object’s velocity. Its the ratio of force over acceleration: m = f/a
What is the definition of Newtons third law
Two interacting objects exert equal and opposite forces on eachother
What is the definition of friction
A force that acts to oppose an objects motion. it always acts in the opposite direction to movement.
What is the definition of Drag
The frictional force caused by any fluid on a moving object (e.g air resistance)
What is the definition of terminal velocity
When the result force acting between the weight and drag acting on a falling object is zero (balanced)
What is the average reaction time of a person
between 0.2 - 0.9 seconds
What are four factor affecting reaction times
1) tiredness
2) drugs
3) alcohol
4) distractions
What is the investigation for reaction time
The ruler drop test
What is the stopping distance equation
stopping distance = thinking distance + braking distance
What are two factors that increase thinking distance
1) faster vehicle speed
2) slow driver reaction times
What are four factors that increase braking distance
1) faster vehicle speed
2) wet or icy weather
3) poor road surface
4) damaged or worn brakes or tyres
What is the definition of the conservation of momentum
In a closed system, total momentum before an event (e.g collision) equals total momentum after an event
What is the equation for momentum
p = mv
p = momentum (Kg m/s) m = mass (Kg) v = velocity (m/s)
