Forces and motion Flashcards
What is the tendency for objects to continue at the same speed in the same direction called?
Inertia
What is distance in a stated direction called?
distance in a stated direction is called displacement.
What is acceleration?
Acceleration is the change in velocity in a certain amount of time ( rate of change in velocity)
What are the units for acceleration?
metres per second per second
m/s”2
What is the equation for acceleration?
change in velocity (final velocity - initial velocity)/
time taken
If an object is moving at a constant velocity, what must that mean about the forces acting upon in?
It’s forward force must EQUAL the force in the opposite direction (provided by air resistance and friction)
What (in terms of forces) must happen to enable an object to accelerate?
It’s forward force must be greater than the opposing force
What (in terms of forces) must happen to enable an object to decelerate?
The opposing force must be greater than it’s forward force.
Describe centripetal acceleration in circular motion.
When something is moving in a circle, the direction is constantly changing towards the circle meaning that it’s velocity is constantly changing. This means it is accelerating however as it’s change in direction of velocity is towards the circle we say acceleration is directed towards the centre of the circle
How do you workout the gradient of a line?
Draw a right angle triangle (hypotenuse is gradient) and divide the vertical by horizontal. Y direction/ x direction.
How to workout the average speed of the journey?
Total distance/ total time
What is meant by the term, “stopping distance”?
The difference in thinking distance and breaking distance
What factors, other than speed, can increase a cars stopping distance?
A longer thinking distance caused by drugs/alcohol. (longer reaction time)
Faulty brakes will increase the breaking distance.
What happens to the temperature of cars brakes when they are applied?
The car’s brakes increase in temperature as energy transfers mechanically from kinetic energy stores of wheels to thermal stores of brakes
