Motion Flashcards
What is the formula for speed?
S= d/t
What is the formula for velocity?
Distance moved in a stated direction (change in position)/ change in time
What is the formula for acceleration?
v-u/ change in time
What is acceleration?
The rate of change of velocity with time
What quantities does velocity have?
Both magnitude AND direction
What is acceleration caused by?
Caused by changing of magnitude and direction of velocity
By changing in direction of velocity
Changing in speed
What can acceleration be?
Speeding up or slowing down
What is negative acceleration called?
Retardation
In a velocity-time graph what does the slope represent?
Acceleration
In a velocity-time graph what does the area under the graph represent?
Displacement
In a velocity-time graph what does the straight line imply?
Uniform acceleration
In a velocity-time graph what do curved lines imply?
Non-uniform acceleration
In a velocity-time graph what does the gradient represent?
The steeper the gradient the higher the acceleration
In a distance- time graph what does the slope of the straight line indicate?
The average velocity
In a distance- time graph what does the straight line imply?
Constant velocity
In a distance- time graph what do curved line imply?
Acceleration
In a distance- time graph what does the positive slope imply?
Motion in the positive direction
In a distance- time graph what does the negative slope imply?
Motion in the negative direction
In a distance- time graph what does zero slope imply?
A state of rest
What is the acceleration of free fall on Earth?
10m/s^2
Describe a parachutist jumping from an aeroplane BEFORE he opens the parachute
- Initially his speed is low
- The air resistance is negligible and he is influenced by his weight only
- He is speeding up at the rate of gravitational acceleration
- As the speed increases air resistance increases
- The acceleration will decrease as resultant force decreases. Until the acceleration becomes zero and the resultant force becomes zero weight=air resistance
- He has reached terminal velocity
Describe a parachutist jumping from an aeroplane WHEN he opens the parachute
- Parachute is opened when there is dynamic equilibrium
- Air resistance becomes much greater than the force of gravity
- The net force up while he is moving down
- He will slow down rapidly and therefore air resistance decreases
- Resultant force decreases
- Weight= air resistance - Terminal velocity
