Forces Flashcards
(28 cards)
What is a force?
A push or a pull that acts on an object.
What’s the difference between contact and non contact forces.
Contact forces are where the objects touch and non contact forces is where they don’t.
Name 3 contact forces.
Tension, friction and up thrust.
Name 3 non contact forces.
Magnetic forces, electrostatic forces and gravitational forces.
What is the unit of force?
Newton.
What is the device for measuring forces?
Newton meter.
What is mass?
Mass is the amount of matter.
What is mass measured in?
Kilograms.
How do you measure mass?
With a top pan balance.
What is the equation to finding out weight?
Weight = mass x gravitational field strength.
What is the GFS on earth?
10 N/M
What do you measure weight with?
Top pan balance.
What do you use to show the forces acting?
Free body diagram.
What is the resultant force?
The overall force acting on an object.
What happens if the resultant force is not 0?
The forces are unbalanced the object could speed up, slow down or change direction.
What is a moment?
The turning effect of a force around a pivot.
What is the equation to calculate moment of a force?
Moment of a force = force x perpendicular distant from the pivot.
What does the principle of moments state?
For the object to be balanced in the clockwise movement is equal to the anti clockwise movement.
What is the calculation to work out pressure?
Pressure = force / area.
What is the unit for pressure?
Pascals (Pa) or N/Cm2
Why does the pressure in a liquid increase with depth?
Because of the increased mass of liquid above that point.
When does an object float?
When it’s weight is equal to its upthrust.
What is the atmosphere?
A thin layer of air round the earth.
When does the atmosphere get less dense?
With increasing altitude.
