Hot water<span> seems to </span>freeze faster<span> than </span>cold water<span>, known as the Mpemba effect. The effect was named after the Tanzanian student who in 1963 noticed that </span>hot<span> ice cream mix </span>freezes faster<span> than a </span>cold<span> one. hope this helped</span>
The pressure acting on an area of 20 m² with force 50 N is 2.5 Nm² and the pressure acting on an area of 0.5 m² with force 50 N is 100 Nm².
The force acting on area of 3 m² with pressure 10 Pa is 30 N.
Explanation:
Pressure acting on any surface is the amount of force experienced by that surface in a given area. So it is the ratio of force to area of the object under consideration.
As here the force is said to be 50 N and the area is said to be 20 m², the pressure will be
![Pressure = \frac{Force}{Area} = \frac{50}{20}=2.5 Nm^{2}](https://tex.z-dn.net/?f=Pressure%20%3D%20%5Cfrac%7BForce%7D%7BArea%7D%20%3D%20%5Cfrac%7B50%7D%7B20%7D%3D2.5%20Nm%5E%7B2%7D)
So, pressure is inversely proportional to the area and directly proportional to the force acting on the surface. As it can be seen that on decreasing the area to 0.5 m², there will be increase in the pressure as shown below,
![Pressure = \frac{50}{0.5} = 100 Nm^{2}](https://tex.z-dn.net/?f=Pressure%20%3D%20%5Cfrac%7B50%7D%7B0.5%7D%20%3D%20100%20Nm%5E%7B2%7D)
Thus, the pressure increased to 100 Nm² from 2.5 Nm² on decreasing the area from 20 m² to 0.5 m².
Similarly, if 10 Pa pressure is acting on an area of 3 m², then the force acting on this region will be the product of pressure with the area.
![Force = Pressure * Area = 10 * 3 = 30 N.](https://tex.z-dn.net/?f=Force%20%3D%20Pressure%20%2A%20Area%20%3D%2010%20%2A%203%20%3D%2030%20N.)
Thus, the pressure acting on an area of 20 m² with force 50 N is 2.5 Nm² and the pressure acting on an area of 0.5 m² with force 50 N is 100 Nm².
The force acting on area of 3 m² with pressure 10 Pa is 30 N.
The net force on the student is A) -294 N
Explanation:
Neglecting air resistance, there is only one force acting on the student: the force of gravity, which is given by
![F=mg](https://tex.z-dn.net/?f=F%3Dmg)
where
m is the mass of the student
g is the acceleration of gravity
In this problem, we have:
m = 30 kg is the mass of the student
is the acceleration of gravity, where the negative sign means the direction is downward
Substituting, we find the force of gravity on the student:
![F=(30)(-9.8)=-294 N](https://tex.z-dn.net/?f=F%3D%2830%29%28-9.8%29%3D-294%20N)
And since this is the only force acting on the student, it is also the net force on him.
Learn more about gravitational force:
brainly.com/question/1724648
brainly.com/question/12785992
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