Our Dynamic Universe Flashcards
Acceleration definition
The rate of change of velocity
What is the gradient of a displacement-time graph
Velocity
What does the gradient of a velocity-time graph equal
Acceleration
What happens to a velocity time graph when an object changes direction
The graph crosses the X axis
How would you find the displacement from a velocity-time graph
The area underneath the graph
What is the definition of a satellite
They are in free fall around a planet or star. They are constantly accelerating but not changing speed- this is because the direction, not the magnitude, of their velocity is changing. The surface of the planet or star curves away from the satellite at the same rate that the satellite curves towards it hence the satellite remains in orbit at a constant altitude.
How to calculate the horizontal of projectiles of the component of velocity
U=Ucos(angle)
Projectiles
Component of velocity vertically
U=Usin(angle)
In projectiles calculate the horizontal distance
d=vt
Speed distance time
Newton’s first law
An object will stay at rest or move with a constant speed unless acted upon by an unbalanced force
Balanced forces
Have the same size of force acting in opposite directions on an object.
Constant velocity=balanced forces
Newton’s second law
F=ma
Unbalanced force equals mass times acceleration.
Newton’s third law
For every action (force) there is an equal and opposite reaction (force).
Friction
Friction is a force which always acts in the opposite direction to an object’s motion.
Tension
Tension is a force that acts both ways at the same the time.
