Elements of Physics

Midterm will cover: Ch 9, 11 & 16

Torque -- Ch. 9

sohcahtoa sin Θ = opp / hyp
cos Θ = adj / hyp
tan Θ = opp / adj

rotational dynamics

torque = force x (perpendicular distance to torque)
unit: Newton-meters (Nm)
direction of torque
counterclockwise Q : positive +
clockwise P : negative -

rigid objects in equilibrium

SFx = 0 | ΣFy = 0 | Στ = 0
linear motion does not change
rotational motion does not change

Center of Gravity HW

Fluids -- Ch. 11

mass density

a fluid is any material that can flow.
ρ = m / V
unit: Kg/m3
specific gravity = ( density of substance ) / ( density of H2O 4°C )
density of water 4°C = 1.000 * 103 Kg/m3

pressure

P = FA
unit: N/m2 or Pascal Pa
1 atmosphere = 1.01 * 105 Pa

pressure & depth

P2 = P1 + ρgh

displacement example

displacement outside of water
water pre-displacement

the weight displaces exactly the same amount of volume of water
water post-displacement