Motion And Forces (paper1) Flashcards
Define distance
The route travelled in m
Define displacement
Shortest distance between 2 points
Define speed
The speed of an object is how quickly it travels over a certain distance
What’s the instantaneous speed
The speed at a particular point
Why do horizontal lines on a distance time graph mean?
That the object is stationary
Why do straight sloping lines mean
The object is travelling at a constant speed
The steeper the line the what?
The faster the object is travelling
How is the speed calculated on a distance time graph
From the gradient of the line
Equation for acceleration
Acceleration = change in velocity(m/s) over time taken(s)
How do you work out the change in velocity
Final velocity - initial velocity
What does a horizontal line mean on a velocity/time graph
The object is travelling at a constant velocity
What does a sloping line show on a velocity/time graph
That the object is accelerating. The steeper the line the faster acceleration
What does a line below the x axis show
An object travelling in the opposite direction
What is the definition for resultant forces
The difference between two forces going in opposite directions
What is Newton’s first law
A moving object will continue to move at the same speed and direction unless an external force acts on it.
What is circular motion
An object moving in a circle has a changing velocity even though the speed remains constant
What is the resultant force that causes the change in direction
Centripetal force, which acts towards the centre of the circle
How can centripetal force be caused
By tension in wires, friction or gravity
Equation for weight
Weight(N)=mass(kg)x gravitational field strength (N/kg)
What does Newton’s third law look at
The interactions between objects-when they touch or interactions such as gravity
What are the pair of forces acting on an object called
Action-reaction forces
What are action-reaction forces always?
They are always the same type of force
What is the difference between action-reaction forces and balanced forces
Balanced forces act on the same object whereas action-reaction forces act on different objects
What is momentum
Is the measure of the tendency of an object to keep moving - or how hard it is to stop the object moving.
