M3C1 Flashcards
What’s the difference between distance and displacement?
Distance - The length of the path moved by an object
Displacement - The length and direction of a straight line drawn from an object’s initial position to its final position
What is the value of g?
g = 9.81 m s^-2
How to work out speed on a distance-time graph?
The speed is equal to the gradient of the line at any given point
How to work out velocity on a displacement-time graph?
The velocity is equal to the gradient of the line at any given point
Two things to remember about velocity-time graphs
Gradient = Acceleration
Area under line = displacement
What are the SUVAT equations?
V = U + AT V^2 = U^2 +2AS S= 1/2(U+V)T S = UT + 1/2AT^2 S= VT - 1/2AT^2 Where; S = displacement U = initial velocity V = final velocity A = acceleration T = time taken
Rearrange S = UT + 1/2AT^2 for A when U = 0
A = 2 (S/T^2)
Note; UT can be ignored when U = 0 because anything times 0 is 0
Define free fall
The acceleration a body feels when falling in the presence of a gravitational feild
Two balls, one of mass 1 Kg the other of mass 10 Kg, are dropped at the same time from the same height. Which hits the ground first?
They both hit the ground at the same time. this is because the inertia of the heavier ball is proportionally greater so it fall at the same rate. The inertia is the resistance of a body to motion.
A ball is thrown straight up into the air. What equation do you use to determine how long it takes to hit the ground?
T = 2(V-U/A)
If we just used T = V-U/A we’d end up with the time it takes to reach it’s maximum height
How to calculate stopping distance?
Stopping distance = Thinking distance + Braking distance
What’s the relationship between speed and braking distance
Braking distance is proportional to the square of speed
