Unit 2: Kinematics Things to Master Flashcards
(11 cards)
What is the definition for distance?
Distance, d, is the length of a path travelled by an object.
What is the definition of displacement?
Displacement, s, is the distance in a specified direction from a reference point.
What is the definition of speed?
Speed is the rate of change of distance travelled with respect to time.
What is the definition of instantaneous speed?
Instantaneous speed is the rate of change of distance travelled at a particular instant.
What is the definition of velocity?
Velocity, v, is the rate of the change of displacement with respect to time.
What is the definition of instantaneous velocity?
Instantaneous velocity is the rate of change of displacement at a particular instant.
What is the definition of acceleration?
Acceleration is the rate of change of velocity with respect to time.
What is the definition of instantaneous acceleration?
Instantaneous acceleration is the rate of change of velocity at a particular instant.
How do you obtain the acceleration form velocity-time graph?
By calculating the gradient
a = (v- u)/ (t - 0)
How do you determine the average velocity and the displacement from the velocity-time graph?
When acceleration is constant in both magnitude and direction, the average velocity is given by:
Average velocity, v ave = (u + v) / 2
Where u is the initial velocity and v is the final velocity
It follows (from the definition of average velocity) that the change in displacement is given by
Change in s = 1/2(u + v) change in t
This is also the area of the trapezium, which proves that the area under the velocity-time graph is the change in displacement of the object divided by change in time.
Hence, the area under the v-t graph gives the change in displacement, regardless of whether the acceleration is uniform or otherwise.
What are the formulas for kinematics?
V square = u square + 2as
S = ut + 1/2 at square
S = vt - 1/2 at square
S = 1/2 (u +v) t
a = (v - u)/t
