P2.3 Motions and forces Flashcards
What is the difference between distance and displacement?
Displacement is a vector, direction isn’t
What is the equation for finding speed?
Speed (m/s) = distance(m) / time(s)
What is a vector?
A quantity that has a magnitude and a direction
What is on the y-axis in a distance-time graph?
Distance
How can you calculate speed in a distance-time graph?
Find the gradient if the line
What do horizontal lines in a distance-time graph mean?
The object is stationary
What is acceleration?
A moving object’s change in velocity
What does getting a negative value when calculating acceleration mean?
The object is decelerating or slowing down
What is the equation for calculating acceleration?
a = (v - u) / t a = (final velocity - initial velocity) \ time
What is acceleration measured in?
m/s^2
Metres per second squared
What does a horizontal line in a velocity-time graph mean?
The object is travelling at a constant velocity
How does the steepness of the line affect acceleration in velocity-time graph?
The steeper the line the greater the acceleration
How do you calculate distance from a velocity-time graph?
You find the area under the graph
What is a force?
A push or a pull that can make objects change speed, shape or direction
Is force a vector quantity?
Yes
When are forces balanced?
When they are equal but acting in opposite directions
What is a resultant force?
When all the forces acting on an object are combined into one
What happens if the resultant force on an object isn’t 0?
The object will accelerate in the direction of the resultant force
What does the size of acceleration from a resultant force depend on?
The size of the force and the mass of the object
How do you calculate force?
F = m x a F = mass (kg) x acceleration
What do you measure force in?
N, newtons
What is gravitational field strength measured in?
N/kg
What is the equation used to calculate weight?
W = m x g W = mass x gravitational field strength
What is the gravitational field strength on Earth?
10N/kg
