Forces-Moving Around

Forces-Moving Around

1. See-Saw!!

   • Pivot movement
   • To balance a pivot
     • Weight=1N
       • Distance from pivot=0.1m
       • Moment=0.1Nm
     • Equal moments
       • Moments are the same as The Turning Effect!Turning Effect is the point where the weights on either end of the pivot become balanced.
       • moments(Nm)=Force(N) x Distance from Pivot (m)
         • example= 1Nx0.2m=0.2Nm
         • example= 2Nx0.1m=0.2Nm
           • Balanced
   • A BIG force and a small distance from pivot
     • Balances...
       • A small force that's a long distance from the pivot

2. Circular Forces

   • Cause
     • A force pulling object towards the centre as they move, when balanced with Gravity, so they move circularly
     • Centrifugal/Centripetal Force
   • It is Pulled tight...
     • Tension in the string
     • Tension is an upward force in the string that balances the downward force of the weight of the object on the end
     • Faster
       • Height of 'bung' increases
       • The width of the circle made increases
     • The tension in the string increases as the speed does too

3. Swinging!!

   • length of pendulum
     • The shorter the pendulum the faster it completes a period!
       • Why?
         • It is naturally closer to the ground so it can travel faster as has less forces acting on it and has less distance to travel a full period.
         • Less Air Resistance
   • Fastest
     • When it is closest to the ground
       • The force of Gravity is at it's strongest-Less forces acting on the object

4. Falling

   • 2 Balls regardless of their weight will hit the ground at the same time
   • A greater surface area=Longer to fall
     • Why?
       • More Space for Air resistance to take effect.
       • More Air Particles hit the surface and stop it accelerating.
       • Bigger the Surface=Less acceleration to No acceleration
   • Closer to ground=Faster to fall
     • Why?
       • There is less air resistance so more acceleration
   • Moon has no atmosphere so no matter their weight or surface area they will still hit the surface of the moon at the same time
   • Parachuter
     • Not open parachute straight away as they would float like a feather (no acceleration)
       • They make a large area so they don't fall too fast.
     • Once they reach Terminal Velocity they release their parachute.
       • Terminal Velocity/Speed is the point when an object is falling and the gravitional pull and the air resistance are balanced and the object stays at the same speed not accelerating/decelerating
       • Once released they decrease their speed fast
         • They then reach Terminal Velocity/Speed again before they land
   • Equation
     • Weight(N)=Mass(kg)xGravity(10)

5. Pressure

   • Area of Contact
     • Small area of contact has a larger pressure than a large force
   • Snow shoes
     • They spread the weight out of a person so less pressure is exerted on the snow so a person doesn't get stuck in deep snow
   • Equation
     • Pressure=Force/Area