P9: Motion Flashcards
What is speed?
A scalar quantity that deduces how quickly an object is moving
What is distance?
How far an object has moved - does not involve direction
What is the formula for speed?
Speed = Distance / time
(m/s) (m) (s)
What are the 4 required typical speeds you need to know?
Walking speed = ~ 1.5 m/s
Running speed = ~ 3 m/s
Cycling speed = ~ 6 m/s
Car on a road = ~ 13 m/s
What is velocity?
The speed of an object in a given direction
What is the velocity of objects moving at constant speed in a circle?
Velocity is constantly changing, even though its speed is constant
How can you determine the speed of an object from a distance-time graph?
Gradient
How can you find the distance from a velocity-time graph?
Area under the graph
How can you find the acceleration from a distance-time graph?
Draw a tangent
What is acceleration?
Change in velocity over a given time (vector)
What is the formula for acceleration?
Acceleration = Change in velocity / time
(m/s^2) (m/s) (s)
What is the formula for uniform acceleration?
v^2 - u^2 = 2as
final velocity² - initial velocity² = 2accelerationdistance
What happens to an object which falls towards the surface of the Earth?
Initially it accelerates to around 9.8 m/s², due to the force of gravity acting on the object
What happens to a skydiver who falls from high altitudes?
Creates friction with air particles (air resistance), after some time, the force of air resistance balances the force of gravity and the object moves at terminal velocity (constant velocity)
What is the terminal velocity?
The highest velocity attained by an object falling through a fluid
