Answer:
We know that force applied per unit area is called pressure.
Pressure = Force/ Area
When force is constant than pressure is inversely proportional to area.
1- Calculating the area of three face:
A1 = 20m x 10 m =200 Square meter
A2 = 10 mx 5 m = 50 Square meter
A3 = 20m x 5 m = 100 Square meter
Therefore A1 is maximum and A2 is minimum.
2- Calculate pressure:
P = F/ A1 = 30 / 200 = 0.15 Nm⁻² ( minimum pressure)
P = F / A2 = 30 / 50 = 0.6 Nm⁻² ( maximum pressure)
Hence greater the area less will be the pressure and vice versa.
To reduce friction between two surfaces, you have to
make the surfaces smoother.
The best way to do that is to introduce a fluid between them,
like grease, oil, or air.
C.) <span>The total mass of an object can be assumed to be focused at one point, which is called its center of "Mass"
Hope this helps!</span>
<span>The word that musicians use for </span>frequency<span> is </span>pitch<span>. The shorter the wavelength, the higher the </span>frequency<span>, and the higher the </span>pitch<span>, of the </span>sound<span>. In other words, short waves </span>sound<span> high; long waves </span>sound<span> low.</span>
The answer to this question lies in the definition of density. One material will just float over another if its density is smaller. If one material is denser than the other, it will sink.
Density can be defined as the mass per unit volume of a substance at a given pressure and temperature.
Thus, for a material to float in water, it does not depend on the weight, or rather on the mass, but on the distribution of the mass by the volume occupied, that is, of the density. The more distributed the mass, that is, the larger its volume, the less dense the object and it will float.
Object C has the lowest density<span>
65 N or 6.5 Kg ------------ 6 N or 6 Kg
This effective mass under water will be its actual mass minus the mass of the fluid displaced.
The buoyant force on a submerged object is equal to the weight of the fluid displaced.
Weight of object - buoyant force on object (the mass of the fluid displaced)
6Kg - 6.5Kg= - 0.5Kg
</span>Answer: C. object C
