Chapter 3 Motion Flashcards
What does the gradient of a distance time graph tell us?
It tells us the speed
How is the instantaneous speed found from a distance time graph?
A tangent is drawn to the graph and the gradient of the tangent is the instantaneous speed
What is the equation to find average velocity?
Avg Velocity = Change in Displacement / Time
What is the difference between a distance-time graph and a displacement-time graph?
The distance in a distance time graph always increases
What can not be found from a distance time graph?
The velocity
What does the gradient of a displacement-time graph represent?
The velocity
What is the equation for acceleration?
Acceleration = Change in velocity / time
What is the gradient of a velocity time graph?
The acceleration
How do you find the displacement on an velocity-time graph?
The area under the graph
What does each of the symbols in the SUVAT equation mean?
S = displacement U = Starting Velocity V = Final Velocity A = Acceleration T = Time
What are the SUVAT equations?
v = u + at s = ut + 0.5at^2 s = 0.5(u + v)t v^2 = u^2 + 2as
What is stopping distance a combination of?
Thinking distance and Braking distance
What is the equation for thinking distance?
Thinking distance = Speed x Reaction time
What is thinking distance?
This is the distance between when the driver sees a reason to stop and the moment they apply the brakes
What is Braking distance?
This is the distance traveled from the time brakes are applied to when the vehicle stops
What is the value of the acceleration due to gravity?
9.81ms-2
What does the acceleration due to gravity apply to?
It applied to all objects with mass
Does mass affect the acceleration of free fall?
No
How can g be determined with a trap door?
Using an electromagnet and a trap door. A ball in a vacuum is held up by an electromagnet and then it is dropped and the timer is started. The timer is stopped when the ball passes through a trap door. Then the distance the ball has traveled is calculated and SUVAT is used to calculate the acceleration of free fall.
What is a more accurate method of working out the value of g?
Using a stroboscope and a camera. The strobe offers regular intervals which are recorded on a camera. Then the change in the position of a dropped object is used to calculate g.
What is the assumption made when calculating projectile motion?
Assumption: There is no air resistance
How can the velocity at any point of a projectiles motion be calculated?
By drawing a tangent to the graph of the motion of the projectile and working out its magnitude
How is the motion of a projectile analysed?
Using SUVAT for the x and y components
