forces

• force is a push , pull or twist motion
• forces are measured in newtons (N)
• gravity , electromagnitism and magnetism are noncontact forces
• air resistance slows things down by pushing against it
• water resistance slows things down in water
• a fluid is a substance that flows
• a compass allways points north
• pressure is the amout of force on a object
• air resistance , water resistance and friction are contact forces
• a contact force comes in contact with something
• a non contact force is when the force can't come in contact
• a newton meter is used to measure the amount of force
• force arrows tell us the direction of the force and the amount of newtons
• when forces are unbalanced it goes in the direction of the stronger force
• when forces are balanced they stay stationary or stay at a constant speed
• a magnet is a force that is attracted to certain metals
• you can increase the force or decrease the surface area to increase pressure.
• you can decrease the force or increase the surface area to reduce pressure.
• a magnet can magnetise or attract other metals
• iron , colbot and nickle are magnetic metals
• the two ends of a magnet are called north and south
• pascals (pa) or N/M² N/cm² are the units for measuring pressure
• magnets have an invisible field around them which shows where it's strongest
• opposite poles attract
• iron fillings can be used to find the magnetic field
• an advantage of designing vehicles with less pressure on their wheels is that the vehicle won't sink into the ground.
• a permenent magnet is a magnet that can't be turned off
• an electromagnet is a coil of wire that is connected to a current
• electromagnets are temporary because they aren't magnetic
• an example of when an area is reduced to create high pressure for something useful is knives for cutting,studs on football boots to stop slipping and lugs on tracks to stop slipping on mud.
• north and south magnets don't depend on electromagnets because they follow the way the currents flowing
• drag is a resistive force caused by the force of fluids making contact with the surface area of a solid object (fluid function)
• the strength of an electromagnet can be increased by increasing the current and increasing the number of coils and increasing the strength of the core
• the 2 types of drag is air and water resistance
• Maglev trains move forward because a computer system is controlling the current in the coils
• Maglev trains reduce friction
• a force multiplyer is a device that increases the force applied to a load by increasing the distance between the force and the load
• a distance multiplier is a device that multiplys with less movement
• air resistance increases as speed increases due to more collisions between particles and the object
• water resistance decreases as speed increases due to less friction from the fluid