Explanation:
When there is no change in chemical composition of a substance then it is known as physical change.
When we say that mass is conserved during a physical change then it means that total mass of the substance or object will remain the same from beginning till the end.
For example, a metal box of mass 20 grams is beaten with hammer. Its shape will change which is a physical change and after beaten with the hammer its mass still remains 20 grams.
Answer:
One way to look at this is to consider the forces acting on any point in a string.
For a very small portion of string F = M a must still hold. As M approaches zero the small portion of string would have to approach infinite acceleration if the net force on that portion of string were not zero.
One generally considers the net force acting on the center of mass of an object not the individual forces acting on each infinitesimal mass composing
the object.
Answer:
v₂ = 16 m/s
Explanation:
We can use the continuity equation, which is as follows:

where,
A₁ = Area of inlet = πd²/4
A₂ = Area of outlet = π(d/2)²/4 = πd²/16
v₁ = velocity at inlet = 4 m/s
v₂ = velocity at outlet = ?
Therefore,

<u>v₂ = 16 m/s</u>
Answer:
Fx = 32.14 [N]
Fy = 38.3 [N]
Explanation:
To solve this problem we must decompose the force vector, for this we will use the angle of 50 degrees measured from the horizontal component.
F = 50 [N]
Fx = 50*cos(50) = 32.14 [N]
Fy = 50*sin(50) = 38.3 [N]
We can verify this result using the Pythagorean theorem.
![F = \sqrt{(32.14)^{2}+ (38.3)^{2}} \\F = 50 [N]](https://tex.z-dn.net/?f=F%20%3D%20%5Csqrt%7B%2832.14%29%5E%7B2%7D%2B%20%2838.3%29%5E%7B2%7D%7D%20%5C%5CF%20%3D%2050%20%5BN%5D)
The answer would defiantly be option D "Nicolaus Copernicus." Copernicus was first to purpose the model of the universe, back in 1543 he presented a heliocentric model of the universe, he also made a geocentric model.
Hope this helps!
Nonportrit