Motion Flashcards
Definition of distance
- Scalar quantity
- A measure of how far an object moves
Definition of displacement
- vector quantity
- total distance in a direction
Definition of speed
- Scalar quantity
The rate of change of distance
Definition of velocity
- vector quantity
- The rate of change of displacement of an object
If a car drives in a circle/loop what is the total displacement?
0 because it finishes back at the original point
What is instantaneous velocity
The gradient in a displacement-time graph (velocity at a particular point in time)
Definition of acceleration
Rate of change of velocity
SUVAT EQUATIONS
v = u + at
v ² = u ² + 2as
s = ut + 1/2at ²
s = 1/2(u+v)t
S=Displacement
V=Final Velocity
U=Initial Velocity
When would you use SUVAT equations?
Only when acceleration is constant
What is the vertical acceleration of a falling object?
9.81
What is the vertical acceleration when an object is thrown up
-9.81
What is an objects vertical velocity at max height?
0
What do you need to remember when calculating the motion of a projectile?
That vertical and horizontal motion are completely different
Equation for calculating velocity
V = △x / △t
Distance in distance (displacement) divided by changing time
Equation for calculating acceleration
a = △v / △t
How is a stationary object represented in a displacement-time graph?
A straight horizontal line
How is constant velocity represented in a displacement-time graph?
A straight line through the origin (the gradient)
How is accelerating represented in a displacement-time graph?
A positively curved line
How is deceleration represented in a displacement-time graph?
A negatively curved line
How is constant velocity represented in a velocity-time graph?
A straight horizontal line
How is constant acceleration represented in a velocity-time graph?
A straight line through the origin (the gradient)
How is constant deceleration represented in a velocity time graph?
A negative gradient - diagonal from top to bottom
How is increasing acceleration represented in a velocity-time graph?
A positively curved line
Define terminal velocity
The highest speed and object can reach when falling through a fluid like air or water
How can terminal velocity be measured?
Using light gates connected to a timer or data locker
What is a projectile?
An object thrown at an angle to the horizontal - moving in both horizontal and vertical planes
How do you calculate the velocity of a projectile?
Analyse horizontal and vertical components separately and assume there’s no air resistance
How would you calculate the initial vertical and horizontal velocities of a projectile?
Horizontal = Vsin0
Vertical = Vcos0
There are no forces acting in the horizontal direction therefore horizontal velocity remains constant and can be analysed through speed=distance/time
Vertical velocity changes due to acceleration, therefore we must use linear motion equations (SUVAT)
What does the velocity equal at the maximum vertical height of a projectile?
0
How do you resolve the final velocity once the vertical and horizontal components are found?
Pythagoras theorem
