Answer:
Explanation:
Mechanical Advantage is the ratio of the distance of the input load (Li)from the pivot to the output load applied to the pivot(Lo)
MA = Li/Le
Given;
Li = 45cm
Lo = 1.8cm
MA = 45/1.8
MA = 25
Hence the mechanical advantage is 25
Also MA is expressed in terms of the force ratio which is the ratio of the Load to the effort applied.
MA = Load/Effort
Given
Load = 1250N
MA = 25
Effort = ?
Substitute
25 = 1250/Effort
Effort = 1250/25
Effort = 50N
Hence the minimum force exerted on the load is 50N
Using the principle of floatation.
u = w............(a)
Upthrust of fluid is equal to the weight of the object.
Let the volume of the wood be V.
The upthrust u, is related to the volume submerged in water, and that is 1/5 of it volume, that is (1/5)V = 0.2V
Formula for upthrust, u = vdg
where v = volume of fluid displaced
d = density of fluid
g = acceleration due to gravity
weight, w = mg
where m = mass
g = acceleration due to gravity
From (a)
u = w
vdg = mg Cancel out g
vd = m
The v is equal to 0.2V, which is the submerged volume. Notice that the small letter v is volume of fluid displaced, and capital V is the volume of the solid.
d is density of fluid which is water in this case, 1000 kg/m³
0.2V * 1000 = m
200V = m
Hence the mass of the object is 200V kg.
But Density of solid = Mass of solid / Volume of solid
= 200V / V
= 200 kg/m³
Density of solid = 200 kg/m³
