Chapter 5B: Observing and recording motion Flashcards
What’s the difference between a scalar and a vector?
Scalars are quantities that only have a size, while vectors (e.g. velocity, momentum, acceleration) have a size and a direction
What is displacement?
A vector quantity that refers to the distance traveled in a straight line from the starting point
What is velocity?
Speed in one particular direction
Name some examples of non-contact forces
Gravity, magnetic forces, static forces
What is the definition of a force?
A push, pull or twist that can make an object change shape, speed up or slow down
What is work?
When a force that is applied to an object moves that object. It is calculated as W (J) = F (N) x D (m). NB: D is distance moved in the line of action of the force
What is a resultant force?
A single force that could replace all other forces acting on an object and still have the same effect
How do you draw a free body force diagram?
Arrows touching the items they act on
Arrows pointing in the direction of the force
Arrow length = force size
What is the extension of a spring?
The difference between its stretched and unstretched length
What is the relationship between the weight placed on a spring and its extension?
Force (N) = k * extension (m)
k = Spring’s unique spring constant
What is a spring’s limit of proportionality?
The point at which its shape changes permanently, and the force added will stop being proportional to extension
How do objects float?
As the object sinks, it displaces water. The water exerts an upwards force on the object equal to the weight of the water displaced. The object keeps sinking until it displaces its weight in water. The upthrust from the water now cancels out the weight of the object, which remains stationary.
How can you predict if an object will float?
If it weighs less than a solid water version of itself would
