# 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.