8-Motion Flashcards
What is displacement?
How far you are from your starting point, and in which direction
What is velocity?
How fast you are going, and in which direction
What is the equation for average velocity?
Change in displacement / time taken
Why is delta used?
To represent change in
What is the area under a velocity-time graph?
The total displacement
What is the equation for acceleration?
Change in speed / time taken
How do you calculate the acceleration at any point in a velocity-time graph?
Draw a tangent at time t.
What are vectors?
Quantities that have both magnitude and direction
What are scalar quantities?
Quantities that have magnitude but not direction
What is acceleration the rate of change of?
Velocity
What is the value of g?
9.8
What does iterative mean?
Step-by step
What is the main problem with the iterative model?
In reality, when an object is in free fall, the velocity and displacement change all the time, NOT in sudden jumps
s = ut + ………?
s = ut + 1/2 at^2
v^2 = ………?
V^2 = u^2 + 2as
When stopping a car, what are the 2 factors to consider?
Human reaction time and the time taken for the car to come to a halt
What does the stopping distance equal?
The breaking distance + thinking distance
When a trolley is rolling down a ramp, what is the value of g parallel?
g X sin theta
Why does an object reach terminal velocity?
At the beginning of its fall a body has little air resistance retarding its motion. There will also be a force acting downwards due to gravity, its weight. As the air resistance is small the resultant downwards force is comparably large. As the body falls, and accelerates, the air resistance increases so the resultant downwards decreases as does the acceleration. Eventually the air resistance upwards balances with the weight downwards and the resultant force is zero. The body then ceases to accelerate and travels at a constant velocity. Refer to F=ma
