Forces (p2) Flashcards
What is meant by a vector quantity?
a quantity with magnitude and direction
What is meant by a scalar quantity?
a quantity with magnitude only
Give 5 examples of vector quantities.
Force, velocity, displacement, acceleration, momentum.
Give 5 examples of scalar quantities.
Speed, distance, mass, temperature, time.
What is a force?
a push or pull that acts on an object due to the interaction with another object.
Is force a scalar or vector quantity?
vector
What are the two types of forces?
Contact and non-contact
What is a contact force?
Forces which act when the object causing the force and the object experiencing the force are touching
What ia a non-contact force?
Forces which act even when the object causing the force and the object experiencing the force are not touching
What is gravity?
The force of attraction between masses.
How are weight and mass different?
Mass is a measure of the amount of matter in an object, so remains the same everywhere.
Weight is a force which acts on an object due to gravity.
A measurement of weight could change with location.
What can be used to measure mass?
A mass balance (balancing scales).
What can be used to measure weight?
A calibrated spring balance (newtonmeter).
Mass and weight are directly proportional. What formula links them?
Weight = mass x gravitational field strength
What is the unit for weight?
Newtons (N).
What is the unit for mass?
kg
What is the unit for gravitational field strength?
N/kg
What is a resultant force?
the overall force acting on an object
How is the resultant force acting on an object calculated?
by adding any forces acting in the same direction, and subtracting any forces acting in opposite directions
When is work done to an object?
when a force moves the object through a distance
What is ‘work done’?
the energy transferred to an object by a force
What equation can be used to find work done?
Work done = force x distance
What unit is equivalent to 1 newton-metre?
1 Joule
What energy store increases when work is done against friction?
thermal store (the object’s temperature increases)