Acceleration and forces arent balanced. Vector sum of all forces
2 of 23
Equilibrium means
not accelerating and forces are balanced
3 of 23
Free body diagrams dont include
the force the object exerts on the rest of the world
4 of 23
4 Examples of forces (vector quantities)
Weight, Normal contact force (reaction), Tension, Friction
5 of 23
Acceleration is proportional to? Acceleration is independent of? and state units of acceleration
Force. Mass. acceleration = ms-2
6 of 23
Resolve a force by
Splitting it into components (VECTORS)
7 of 23
Three forces acting on a point in equilibrium...
form a triangle
8 of 23
drawing forces in vector addition
vector arrows 'tip to tail'
9 of 23
The mass of a body makes it resist Changes in motion. What does increasing mass do to its inertia
greatens it (greater resistance to a change in velocity) (gravitational field strength doestn affect mass)
10 of 23
What is weight?
W=mg. The force experienced by a mass due to a gravitational field.
11 of 23
Define center of mass
the single point that you can consider an objects whole weight to act through. Balances around this point. (plumbline experiment)
12 of 23
Define friction and state the two types
a force that opposes motion. Converts kinetic energy into heat. Contact (solid) and Fluid (drag - liquid and gas)
13 of 23
Fluid friction depends on
viscosity (higher V lower TV), speed, shape/size
14 of 23
The heavier an object is, the faster it reaches terminal velocity (drag). An object reaches terminal velocity when
Friction force = Driving force (works for water aswell)
15 of 23
Density doesnt vary with size or shape. Define Density and state its units
mass per unit volume kgm-3. An object will float if it has a lower density than that of the liquid.
16 of 23
Define Pressure and state units
Force per unit area Pa / Nm-2. Also P=hpg (h is depth, p is density of fluid, g is acceleration due to gravity)
17 of 23
Explain Upthrust
upwards force that fluids exert on objects that are submerged. P=hpg and the top and the bottom of the object are at different depths. Upthrust = Weight of fluid displaced
18 of 23
Define a moment/torque
the turning effect of a force. Moment (Nm) = force (N) x perpendicular distance from pivot (m)
19 of 23
State the principle of moments
for a body to be in equilibrium, the sum of the clockwise moments about any point equals the sum of the anticlockwise moments about the same point
20 of 23
What does the effort force do in a lever
acts against a load force by means of a rigid object rotating around a pivot
21 of 23
Define a couple
a pair of forces of equal size which act parallel to each other but in different directions
22 of 23
A couple doesnt produce any resultant linear force, what does it produce and what is the equation?
a turning force.Torque of a couple (Nm) = size of one of the forces (N) x perpendicular distance between the forces (m)
23 of 23
Other cards in this set
Card 2
Front
Resultant force means
Back
Acceleration and forces arent balanced. Vector sum of all forces
Comments
No comments have yet been made