Dynamics Flashcards
Name Scalars
Speed
Distance
Mass
Time
Energy
Name Vectors
Velocity
Displacement
Weight
Force
Acceleration
What is a scalar?
Scalars are quantities defined by their size/magnitude only.
What is a vector?
Vectors are quantities which are defined by their size/magnitude and direction.
How are vectors added?
Nose to tail.
How do you calculate the average speed?
- Measure the distance between a and b
- Measure the time taken to travel between a and b
- Use v = d/t
How do you calculate the instantaneous speed?
- Measure the length of the card/trolley
- Measure the time taken for the card/trolley to travel through the light gate
- Use v = d/t
What is the acceleration?
The acceleration is the rate of change of velocity.
What does 5ms-2 mean?
The velocity is increasing by 5ms-1 every second.
What does -3ms-2 mean?
The velocity is decreasing by 3ms-1 every second.
How do you measure the distance/displacement from a velocity/time graph?
Find the area under the graph.
How do you calculate the acceleration?
a = v - u / t
What can a force change?
The speed, direction or shape of an object.
What is the force that acts down on a object called?
Weight or the force of gravity.
What is the force that always acts against a moving object?
Friction.
What is the force in a stretched rope or wire called?
Tension.
What is the definition of gravitational field strength?
The force of gravity per unit mass.
What can be used to decrease friction?
- Making the surfaces smooth
- Separating the surfaces using lubricant.
- Streamlining the objects.
What is Newton’s 1st law?
An object will remain stationary or travel at a constant speed unless acted on by an unbalanced force.
What is Newton’s 2nd law?
if the forces on an object are unbalanced an object will accelerate or decelerate.
What is Newton’s 3rd law?
For every action there is an equal but opposite reaction.
What is meant by a terminal velocity?
Air friction = weight
Why does a projectile take a curved path?
A constant horizontal velocity.
A constant vertical acceleration.
