Kinematics Flashcards
What are the 2 kinematic equations you need to memorize?
v= u+at
s=1/2(u+v)t
Definition of distance
Distance is the total length covered by an object irrespective of the direction of motion.
Definition of displacement
Displacement is the change in the position of the object relative to its initial position.
Is distance a scalar or vector quantity?
Scalar
Is displacement a scalar or vector quantity?
Vector
What is the SI unit of distance?
metre(m)
What is the SI unit of displacement?
metre(m)
A car travels 3.0km due east from point O to A and then a further 3.0km due north of A. Determine the distance covered and its displacement.
Distance: 6.0km
Displacement:4.2km(2sf)
Definition of speed
The speed of an object is defined as the rate of change of its distance travelled with respect to time.
Definition of velocity
The velocity of an object is defined as the rate of change of its displacement with respect to time.
Is speed a scalar or vector quantity?
Scalar
Is displacement a scalar or vector quantity?
Vector
What is the SI unit of speed?
metre per second(m s^-1)
What is the SI unit of velocity?
metre per second(m s^-1)
Definition of instantaneous speed
Instantaneous speed of an object at a particular instant is the rate of change of distance with respect to time at that instance.
Definition of instantaneous velocity
Instantaneous velocity of an object at a particular instant is the rate of change of displacement with respect to time at that instance.
How do you know if a body is said to be moving with constant velocity?
A body is said to be moving with constant velocity if the displacement changes at a constant rate.
Definition of acceleration
The acceleration of an object is defined as the rate of change of its velocity with respect to time.
Is acceleration a scalar or vector quantity?
Vector
What is the SI unit of acceleration?
metre per second squared
How do you find the average acceleration?
Change in velocity/Total time taken
How do you find instantaneous acceleration?
dv/dt
3 reasons why there can be a change in velocity
1)A change in magnitude
2)A change in direction
3)A change in both magnitude and direction simultaneously
What is the acceleration of free fall on the Earth’s surface?
9.81 m s^-2
Difference between acceleration and deceleration
Acceleration is the change in velocity. Deceleration is slowing down.
What does the instantaneous velocity mean in the displacement-time graph?
Gradient of the tangent at a point on the graph
What does it mean when the tangent is steeper in a displacement-time graph?
The gradient is larger, the velocity is higher.
What does the gradient of the velocity-time graph at any point of the velocity-time graph?
Instantaneous acceleration
What does the area under a velocity-time curve give?
Change in displacement
What does the are under the acceleration-time graph give?
Change in velocity
Give the 3 formulas of motion
v = u + at
v^2 = u^2 + 2as
s = ut + 0.5at^2
What is the magnitude of vector u?
(ux ^2 + uy^2) ^ 0.5
How do you find the direction of vector
tan θ = uy/ux
For an object projected at an angle from the ground, for the horizontal direction, what is the initial velocity?
ux = u cos θ
For an object projected at an angle from the ground, for the horizontal direction, what is the velocity at the highest point?
vx = ux
For an object projected at an angle from the ground, for the horizontal direction, what is the acceleration?
ax = 0
For an object projected at an angle from the ground, for the horizontal direction, what is the displacement?
sx
For an object projected at an angle from the ground, for the vertical direction , what is the initial velocity?
uy = u sin θ
For an object projected at an angle from the ground, for the vertical direction ,what is the velocity at the highest point?
vy = 0
For an object projected at an angle from the ground, for the vertical direction, what is the acceleration?
-9.81 m s^-2
For an object projected at an angle from the ground, for the vertical direction ,what is the displacement?
sy
For an object projected horizontally off a cliff for the vertical direction ,