Quiz 9 Flashcards
If an object is moving and there is a resultant force of 0N acting on it,what does the object do?
Moves at constant velocity
Describe the motion of an object in equilibrium
Constant velocity or stationary
What does the area under a velocity-time graph equal?
Distance travelled
What does a horizontal line on a velocity-time graph show?
Constant speed
When an object is moving at a constant speed in a circle,its velocity is changing. Why?
The object is changing direction and velocity is a vector quantity
How does speed affect stopping distance?
Greater speed means greater stopping distance
Why do wet/icy conditions and poor brake/tyre condition increase braking distance?
They decrease friction
What type of quantity is displacement?
Vector
What is a system?
A group of objects that interact
Describe the motion of a falling object when weight=air resistance
Terminal velocity
Why physics quantity means how far an object moves, regardless of direction?
Distance
How do you calculate the acceleration from a velocity-time graph if the line isn’t straight?
Draw a tangent and find the gradient of the tangent
Why does a falling object accelerate initially?
Weight is bigger than air resistance
State the equation used for Newtons 2nd law using symbols
F=ma
When an object is moving at a constant speed in a circle(includes half circle such as turing corner),it is accelerating. Why?
The object is changing direction,velocity is a vector quantity so velocity is changing
What is the typical value of speed for a car
25m/s
What is a typical value of speed for a plane
250m/s
What is a typical value of speed for a trian?
55m/s
