forces and fields
name the three types of force
push, pull twist
What is the name for the tiny particles that has a negative charge and plays a role in making objects attract or repel each other?
electrons
name a situation when the effects of gravity are unbalanced
dropping a book from a height and watching it fall
what does the term 'attractive force mean'
a force that pulls objects towards each other
what is an electromagnet?
A type of magnet that is created by running an electric current through a coil or wire. Electromagnets can be turned on and off by controlling the flow of electricity.
what does this mean:
the strength of a force varies at a distance
the closer an object is to a force to greater the force, the further away from the force the less it acts on an object
when charged objects are brought close to each other, what do they do?
charged objects can either attract or repel each other based on their charges
how does earths gravity influence the motion of objects?
earths gravity pulls objects towards its center, giving them weight
what happens when magnetic poles are brought close together
like magnetic poles repels each other, while opposite poles attract each other
provide an example of an everyday device that uses electromagnets and explain its function
MRI to take internal images of the body
speakers to generate sound
locks to open and close doors
what is this:
an area of space where objects are affected by a non-contact force
field
the electrical potential difference between the two object causes electrons to jump across the small gap between them, creating a brief flow of current. This sudden flow of electrons is what you feel as a zap and see as a spark.
whats the difference between mass and weight
mass is the amount of matter in an object, while the weight is the force due to gravity acting on it
how do magnets and electromagnets differ in terms of their ability to control their magnetic strength?
electromagnets can vary their strength by changing the current, while magnets have a fixed strength
what can an electromagnets do that permanent magnets cannot?
turn on and off, change direction of poles and size of field
what is the difference between gravitational fields and electromagnetic fields?
gravitational fields are always attractive, while electromagnetic fields can be either attractive or repulsive based on charge.
what is the biggest difference between conductors and insulators?
conductors allow charge to flow easily, while insulators resist charge flow
explain why an astronaut's mass remains constant whether on earth or in space but their weight changes
mass is an intrinsic property that doesn't change, while weight depends on the strength of the gravitational field
what is one use for an attractive force and a repulsive force
Attractive Force - magnetic locks (use key card to open - electromagnets)
Repulsive Force - Magnetic Levitation Trains
what features determine the strength of an electromagnet
- type of core metal
- amount of electrical current
- number of coils around the metal
There are 2 objects. Object A is 5kg and object B is 10kg. If you apply the same force to both objects, which one will experience greater acceleration, and why?
object a, because it has less mass
if the movement of electrons creates electrostatic charge, what would be the overall charge on an object that loses electrons?
positive
if objects are attracted to one another due to gravitational forces, provide a reason why planets orbit around the Sun rather than crashing together
An object's momentum and the force of gravity have to be balanced for an orbit to happen. If the forward momentum of one object is too great, it will speed past and not enter into orbit. If momentum is too small, the object will be pulled down and crash.
Explain how the Earth's magnetic field is generated
The Earth's magnetic field is primarily generated by the motion of molten iron in the outer core of the Earth. This motion, driven by heat from the Earth's interior, creates electrical currents that generate the magnetic field through a process known as the geodynamo.
how does a doorbell use electromagnets
Doorbells use electromagnets to create sound by attracting and releasing a metal piece when the circuit is completed