Forces Flashcards
What is hooke’s law
Hooke’s law states that within the limit of proportionality, the extension produced in a material is directly proportional to the load applied
- F = kx
Work done by stretching material obeying hooke’s law
W = 1/2(kx^2)
What is the area under the F-x graph
Elastic potential energy stored in material
What is a moment of a force?
The moment of a force is defined as the product of the force and the perpendicular distance between the axis of rotation and the line of action of the force
- τ = r x F
What is a couple
A couple is a pair of equal and opposite forces acting on a body and their lines of action do not coincide
What is the torque of a couple
The torque of a couple is the product of one of the forces and the perpendicular distance between their lines of action
- τ = d x F
What are the conditions for translational equilibrium
- Resultant force is 0
- Resultant moment about any axis is 0
What is hydrostatic pressure?
It is the pressure that is exerted by a fluid at equilibrium a given point within the fluid, due to the force of gravity. It increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.
What is the pressure p due to a fluid at depth h
p = ρgh
What is the actual pressure at a depth h
p = ρgh + patm
What is the formula for upthrust
upthrust = ρgV = weight of fluid displaced
What is the archimedes principle
Upthrust is equal to the weight of the fluid displaced by a submerged or floating object
