Kinematics Flashcards
Define kinematics
The study of how an object moves
Formula and unit for speed
Speed = distance ÷ time
Units: m/s or km/h
Is speed a vector or scalar quantity?
Scalar
Formula and unit for velocity
Velocity = displacement ÷ time
Units: m/s and direction
Is velocity a vector or scalar quantity?
Vector
Define constant/uniform speed
An object has constant speed if it covers equal distance in an equal interval of time
Formulas and units for average speed
Average speed = total distance ÷ total time
OR
Average speed = initial speed + final speed ÷ 2
Units: m/s or km/h
Formula and units for acceleration
Acceleration = final velocity - initial velocity ÷ time
Units: m/s^2
Define uniform acceleration
A body has uniform acceleration when its velocity increases equally in equal time intervals
What does it mean when acceleration is negative?
There is deceleration
What are the ways to calculate distance on a graph?
By using the formula Distance = speed x time or Distance = area under graph
Describe terminal velocity with air resistance
When an object is dropped in air, its velocity will increase due to its weight. When velocity increases air resistance increases until it is equal to its weight. The resultant force will be 0. When R.F = 0 the object falls with constant velocity (terminal velocity)
Describe terminal velocity without air resistance eg. in a vacuum
The velocity of the body increases uniformly. The acceleration remains constant during the fall and the velocity keeps on increasing uniformly until it suddenly drops to zero on hitting the ground
Define stopping distance
It is the minimum distance required to stop a vehicle in an emergency
Formulas for stopping distance
Stopping distance = thinking distance + braking distance
