Motion Flashcards
What is an object’s speed, average speed and instantaneous speed?
-Speed: How fast something is moving, regardless of direction
-Average Speed: The total distance covered over the the total time elapsed
-Instantaneous Speed: The speed of an object at any given point in time
What is an object’s velocity, displacement and acceleration?
-Velocity: The rate of change of an object’s displacement
-Displacement: How far an object’s travelled from its starting point in a given direction
-Acceleration: The rate of change of an object’s velocity
What is the force from Earth?
-All object’s experience a force due to Earth’s gravitational field which depends on the object’s mass
-When the only force acting on the object is Earth’s gravitation field/weight it undergoes freewill, and will accelerate towards the ground
How can you make the calculation for gravity more accurate?
-Large distances, and using a computer can remove uncertainties
-Use a small and heavy ball to reduce the air resistance
What is strobe photography?
-A camera is set to take a long exposure
-A strobe light flashes repeatedly and the projectile is released
-The light lights up the object at regular intervals which means the projectile appears multiple times in the same photograph in a different position
-You can calculate how far the object travels between flashes of the strobe, and se the time between to calculate velocity
What are features of the displacement-time graph?
-Velocity is the gradient
-If the gradient is straight then the acceleration is uniform
-A larger acceleration will have a steeper gradient
What are features of a velocity-time graph?
-The gradient tells acceleration
-Uniform acceleration, is always a straight line
-Displacement is the area under the velocity-time graph
What are features of acceleration-time graph?
-The height gives the object’s acceleration
-The area gives the change in velocity
-A negative acceleration is deceleration
-If a = 0 the object is moving at a constant velocity
