P8 Forces In Balance Flashcards
What is displacement?
Distance without change of direction.
What are the vectors?
Acceleration, gravitational field strength, force, momentum, weight, velocity + displacement.
What are the scalars?
Speed, distance, time, mass, energy + power.
What is a scalar?
Physical quantities that have size, no specific direction.
What is the size of a quantity?
Its magnitude.
What is a vector?
Physical quantities that have direction.
What does a vector have?
Magnitude + direction.
What does a scalar have?
Magnitude only.
What is Newton’s third law of motion?
When 2 objects interact with each other, exert equal + opposite forces on each other.
What is the unit of force?
The newton (abbreviated as N).
What is a resultant force?
Single force that has same effect as all forces acting on an object.
What does Newton’s first law state?
If force acting on an object are balanced, resultant force on object is 0.
If object is at rest, stays stationary.
If object moving, keeps moving with same speed and in same direction.
What is the moment of the force?
Turning effect of force.
What can the moment of the force be increased by?
Increasing size of force.
Using spanner with long handle.
What is the load of the object?
Weight of the object.
What is the effort?
Force person applies to crowbar.
How can you work out the moment of a force?
Using the equation:
Moment, M (newton metres, N m)= force, F (newtons, N) * perpendicular distance from line of action of force to pivot, d (metres, M).
What is the centre of mass of an object?
Point at which its mass can be thought of as being concentrated.
How can you find the centre of mass of a symmetrical object?
For flat symmetrical object centre of mass along axis of symmetry.
What does the principle of moments state?
Sum of all clockwise moments about any point = sum of all anticlockwise moments about that point.
What equipment do you need to test an incline?
1) Use newton-meter to measure weight of trolley + the force, add weights to trolley to find out how force changes as weight of trolley increased.
2) Repeat test with board at alternative angle to laboratory bench.
3) Record all measurements in table, + plot graph of results.
4) Write down conclusions made from graph about relationship between force + weight.
