In: Physics
a. What is the scale reading if theblock is in air?
V = 10 cm x 10 cm x 10 cm = .1m x .1m x .1m = .001m^3
density of steel = 7900kg/m3
Part a
formula .... ρ=m/v.... desnity = ρ, mass=m,V=volume
ρV=m....solve for mass
7900 kg/m3 × .001m^3 = 7.9 kg
m=7.9kg..therefore, the spring scale must read the masses'weight
F=mg= (7.9kg)(9.8m/s^2) = 77.42 N
Part b.
density of oil : 900kg/m^3 *(although the densities of oilvary)
Bouyant Force = Fb
w- weight of mass in air
w' - apparent weight (weight of mass in water)
w' = w-Fb
Fb = p*gV
*(of fliud)
Fb= (900kg/m^3)(9.8m/s^2)(.001m^3)
Fb = 8.82N
w= 77.42N (from part a)
w'= w-Fb
= 77.42N - 8.82N
= 68.6N