3.1 Motion Flashcards
Define speed, the equation used to calculate speed, and the respective SI units
The rate of change of distance
Speed=distance/time
m/s
Define displacement
The distance an object has travelled in a given direction, so it is a vector quantity with both magnitude and direction
Define velocity, the equation to calculate it, and the respective SI units
The rate of change of displacement, speed in a given direction
change in displacement/time
m/s
Define celebration, the equation used to calculate acceleration and the respective SI units
The rate of change of velocity
acceleration=change in velocity/time
m/s^2
What does a straight, horizontal line represent on a displacement-time graph?
A stationary object
What does a line with a constant, non-zero gradient represent on a displacement-time graph.
An object moving with constant velocity
What does a curved line represent on a displacement-time graph?
Acceleration (increasing gradient)
Deceleration (decreasing gradient)
What does a straight, horizontal line represent on a velocity-time graph?
An object moving with constant velocity
What does a line with a constant, non-zero gradient represent on a velocity-time graph?
An object that is acceleration (positive gradient) or decelerating (negative gradient)
What does the area under a velocity time graph represent?
Displacement
What does the area under an acceleration-time graph represent?
Velocity
Describe how the terminal velocity of an object can be determined using light gates
-set up light gate vertically and measure distance between them
-connect to data logger then release an object from rest above them, measuring time taken for object to travel between two gates
-using time and known distance, calculate the velocity of the falling object
Describe how light gates can also be used to investigate conservation of momentum
-place two carts on a linear air track (to reduce friction) with repelling magnets so that they do not stick together
-attach card to top of each cart so that they break the beams of the light gates when they pass
-keep one cart stationary and push other towards it, measure velocity before collision
-measure velocity of both carts after collision and calculate momentum before and after
Define ‘g’
The acceleration of free fall, acceleration of an object in response to the gravitational attraction between Earth and the object
Describe the experiment in which one can determine ‘g’ using an electromagnet
-an electromagnet holds a steel ball suspended a measured distance above a surface p, start timer when electromagnet deactivated, stop when surface is hit
-as initially at rest, u=0
-known distance and time
-SUVAT equation s=ut+1/2at^2
-calculate a which is g
