Hooke's Law
- States that the magnitude of the force F exerted by a spring on a body attached to the spring is proportional to the extension x of the spring from equilibrium provided the proportional limit of the spring is not exceeded
- F = kx
- Elastic potential energy, U = 1/2 k x^2
Upthrust or Buoyant Force
- Pressure due to fluid is force acting per unit area by the fluid
- P = ρgh
- When surface of fluid experiences atmospheric / external pressure
P = ρgh + Po
- Upthrust is the net upwards force exerted by a fluid on a body fully or partially submerged in the fluid
Archimedes' Princinple
- For a body submerged in a fluid, the upthrust acting on the body is equal to the weight of the fluid displaced
U = ρVg
Principle of Floatation
- For a body floating in a fluid, the weight of the fluid displaced by the body is equal to the weight of the body
Translational Equilibrium
- When a body is stationary or moving at constant velocity
- Net external force acting on the body is zero
Rotational Equilibrium Principle of Moment
- For a body to be in rotational equilibrium, the sum of clockwise moments about any points must be equal to the sum of anticlockwise moments about that same point
- Net moments acting about a point is zero
Moment of a force
- product of the magnitude of a force and the perpendicular distance of the line of action of the force to the point
- moment = Fd
Static Equilibrium
- Net External Force acting on the body = 0
- Net moment acting on the body = 0
Equilibrium for 3 Force System
- Line of action of all3 forces must intersect at the same point
Couple
- A pair of forces, which are equal in magnitude but opposite in direction, whose line of actions are parallel but seperate
- Produces only rotation but no translation
- Moment of a couple is the product of the perpendicular distance between the lines of actions of the two fores and the magnitude of one of the forces
- States that the magnitude of the force F exerted by a spring on a body attached to the spring is proportional to the extension x of the spring from equilibrium provided the proportional limit of the spring is not exceeded
- F = kx
- Elastic potential energy, U = 1/2 k x^2
Upthrust or Buoyant Force
- Pressure due to fluid is force acting per unit area by the fluid
- P = ρgh
- When surface of fluid experiences atmospheric / external pressure
P = ρgh + Po
- Upthrust is the net upwards force exerted by a fluid on a body fully or partially submerged in the fluid
Archimedes' Princinple
- For a body submerged in a fluid, the upthrust acting on the body is equal to the weight of the fluid displaced
U = ρVg
Principle of Floatation
- For a body floating in a fluid, the weight of the fluid displaced by the body is equal to the weight of the body
Translational Equilibrium
- When a body is stationary or moving at constant velocity
- Net external force acting on the body is zero
Rotational Equilibrium
Principle of Moment
- For a body to be in rotational equilibrium, the sum of clockwise moments about any points must be equal to the sum of anticlockwise moments about that same point
- Net moments acting about a point is zero
Moment of a force
- product of the magnitude of a force and the perpendicular distance of the line of action of the force to the point
- moment = Fd
Static Equilibrium
- Net External Force acting on the body = 0
- Net moment acting on the body = 0
Equilibrium for 3 Force System
- Line of action of all3 forces must intersect at the same point
Couple
- A pair of forces, which are equal in magnitude but opposite in direction, whose line of actions are parallel but seperate
- Produces only rotation but no translation
- Moment of a couple is the product of the perpendicular distance between the lines of actions of the two fores and the magnitude of one of the forces