Forces Flashcards
What is a force?
Push/pull/twist that cannot be seen, but can see the effect on an object.
What are the 4 effects of a force?
- Change the position
- Change the direction/speed
- Change the shape (deform)
- Cause rotation
What are the two types of forces? Explain each.
- Contact forces - forces that occur when 2 objects are touching
- Non-contact forces - forces that occur even though objects are separated by distances.
Name 7 contact forces.
- Air resistance
- Friction
- Tension
- Reaction
- Applied force
- Spring force
- Normal force
Name 3 non-contact forces.
- Magnetic force
- Electrostatic force
- Gravitational force
What is the symbol for force?
F (NOT “f”)
What is the SI unit for force?
Newtons/N (NOT “n”)
Name 2 things to measure the magnitude of relatively small forces.
Spring balance
Newton meter
What is magnitude?
Size.
What are Newton’s 3 laws of motion?
LAW 1: An object will remain still/keep travelling at a constant velocity when all the forces acting on it are balanced (equal/cancel out).
LAW 2: An object will accelerate in the direction of the resultant force when all the forces acting on the object are unbalanced.
LAW 3: When 2 objects interact, the forces they exert on each other are equal in size and opposite in direction.
What is a vector?
A. Despicable Me Movie character
B. Quantity that has a magnitude
C. Quantity that has a magnitude and direction
D. Quantity that has a direction
C.
What is a scalar?
A. A word
B. Quantity that has a magnitude
C. Quantity that has a magnitude and direction
D. Quantity that has a direction
B.
What are balanced forces?
Forces that are the same size, but in opposite directions.
What are unbalanced forces?
Forces that are not equal and opposite, which results in a change in speed/direction.
What is equilibrium?
When the resultant force equals zero.
What is a force diagram?
Displays all the forces acting on an object as arrows, pointing in the direction of the effect. This can be simplified by using the object’s centre of gravity.
What is friction?
Resistance to motion.
What are the 3 effects of friction?
Slows moving objects down
Causes objects to heat up
Wears surfaces out
How is friction created?
Friction is created when two touching objects/surfaces move past each other.
How can friction be reduced?
Lubrication and streamlining.
What is air resistance?
Friction that occurs in the air.
What is water resistance?
Friction that occurs in the water.
Air + water resistance = _______.
Drag.
What is thrust?
Force that pushes an object forward.
What is upthrust?
Force that pushes an object upwards in a liquid/gas = buoyancy.
What is tension?
Force exerted by a rope, string, chain, cable, spring etc.
What is extension?
The amount that an object gets longer when you stretch it.
What is fluid?
A substance that continually flows under an applied sheer stress, or external force.
What is mass?
Amount of matter in an object that remains the same throughout the universe.
Mass is a scalar/vector.
Scalar.
What is the symbol for mass?
m (NOT “M”)
What is the SI unit for mass?
kilogram or kg (NOT “KG” or “Kg” or “kG”)
What equipment is used to measure mass?
Balance.
What is weight?
Gravitational force that the object’s mass experience in a gravitational field.
Weight is a scalar/vector.
Vector.
What is the symbol for weight?
W (NOT “w”)
What is the direction for weight?
Towards the center of the Earth (on Earth).
What equipment is used to measure mass?
Spring balance.
Is the weight of an object unique to the gravitational field?
Yes.
What is the formula for weight?
W = m x g
W = weight m = mass g = gravity
What is the centre of gravity?
Point through which all the weight of an object seems to act.
