Forces - PHYSICS Flashcards
What is displacement?
The overall distance travelled in a certain direction
What are vectors
Special quantities in science that both have a size and a direction
What is a scalar?
Something that has a size/magnitude but bi direction
What is acceleration?
A change in an objects velocity
When the gravitational field is stronger, is the weight larger or smaller?
Larger
What equation connects weight, mass and gravitational field strength?
Weight = mass X gravitational field strength
Contact forces can only exist when…
The objects are touching
Contact or non-contact? Thrust
Contact
Contact or non-contact? Gravitational/weight
Non-contact
Contact or non-contact? Friction
Contact
Contact or non-contact? Air resistance
Contact
Contact or non-contact? Tension
Contact
Contact or non-contact? Elasticity
Contact
Contact or non-contact? Electrostatics
Non-contact
Contact or non-contact? Magnetism
Non-contact
Contact or non-contact? Upthrust
Contact
Contact or non-contact? Lift
Contact
Contact or non-contact? Water resistance
Contact
What is Newton’s third law?
Every action has an equal and opposite reaction
What is Newton’s first law of motion?
If the resultant forces are zero
-the forces are balanced
-If the object is already moving it will continue to do so at a constant speed
-if not it will remain stationary
What is the objects centre of mass?
The point at which the weight of an object appears to act from
For unsymmetrical objects how do you work out the centre of mass?
You hang them from different points along a plumb line and draw these lines of the object and where they cross over is the centre
Where is the centre of mass for a symmetrical object?
Where the lines of symmetry cross
What is Newton’s second law?
Force is directly proportional to acceleration.
What equation links force, mass and acceleration?
Force = mass X acceleration
What is the equation for acceleration?
Final velocity- initial velocity/ time taken
What does precise data give you?
Results which are similar to each other if you repeat the measurements
What does accurate data give you?
Data which is close to the true value
What are random errors?
Errors made by the person carrying out the measuring and are normally down to timing incorrectly. Affect precision
What are systematic errors?
Errors which are the same for every measurement. Faulty equipment
A larger resultant force leads to a ————— acceleration
Larger
A larger mass leads to a ———— acceleration
Smaller
As mass increases, acceleration…..
Decreases
What’s the equation linking resultant force, mass and acceleration
Resultant force = mass X acceleration
What is terminal velocity?
The maximum velocity that a freely falling object will eventually reach
What does the mass of an object depend on?
The quantity of matter in it
What is stopping distance?
The distance an object travels while it is attempting to stop
Stopping distance = ———+———
Thinking distance + braking distance
What can affect thinking distance?
Drugs
Alcohol
Tiredness
Distractions
Age
What can affect braking distance?
Condition of breaks
Wet/icy roads
Road conditions
Tyre conditions
What is the equation for spring contant?
Force = spring constant X extension
What is the equation for elastic potential energy?
EPE = 1/2 X spring constant (k) X extension^2
K = 1/gradient
Spring contant is 1/gradient
How do you work out gradient?
Rise /run
What is momentum?
The tendency of the object to keep moving in the same direction
The greater the momentum the ——— it is to stop
Harder
Distance =
Speed X time
What does the area under the velocity time graph tell you?
The distance travelled
