Dynamics Flashcards
Scalar quantities
Distance, speed, time, energy, temperature, pressure, mass, current, volume, current, volume, voltage, area, resistance, frequency
Vector quantities
Displacement, velocity, acceleration, force, weight
What is Newton’s first law?
If balanced forced are applied to a body that is not moving, the object will remain at rest
AND
If balanced forces are applied to a body that has velocity, the object will remain moving at that constant velocity
What is Newton’s second law?
The acceleration of an object (produced by an unbalanced force) is:
Directly proportional to the magnitude of the unbalanced force,
In the same direction as the unbalanced force
Inversely proportional to the mass of the object
(F = ma)
What is F = ma
One Newton is defined as the force that makes a mass of 1 kg accelerate at 1 m s^-2
What is Newton’s third law?
If an object A exerts a force (the action) on object B, then object B will exert an equal, but opposite force (the reaction) on object A
How does a rocket take off?
The rocket exerts a force upwards whilst exhaust fumes from the fuel exerts an equal force in the opposite direction (downwards)
How can you measure average and instantaneous speed and acceleration?
Trolley on a ramp with a light gate.
Define acceleration
How quickly velocity changes
What are the effects of forces?
The shape of an object
The speed of an object
The direction of movement of an object
What are the factors that friction depends on?
How rough the two surfaces are
The size of the force between the two surfaces (how hard they are pressed together)
free fall
Free fall is the motion of an object where gravity is the only force acting on it.
terminal velocity
Terminal velocity occurs when a maximum velocity is reached, where the force of drag (air resistance) is balanced with the force of gravity. As these forces are balanced, there is no acceleration and so terminal velocity is reached.
