The viscous force on an object moving through air is proportional to its velocity.
The only forces acting on an object when falling are air resistance and its weight itself. The weight acts vertically downwards whereas air resistance acts vertically upward.
Let F be the viscous force due to air molecules, B be buoyant force due to air and W be the weight of falling object. Initially, the velocity of falling object and hence the viscous force F is zero and the object is accelerated due to force
(W-B). Because of the acceleration the velocity increases and accordingly the viscous force also increases. At a certain instant, the viscous force becomes equal to W-B. The net force then becomes zero and the object falls with constant velocity. This constant velocity is called terminal velocity.
Thus at terminal velocity, air resistance and force of gravity becomes equal.
Answer:
All three pendulum will attain same velocity
Explanation:
All three pendulum will attain same velocity irrespective of their mass difference in isolated system (means where air drag are negligible) and at same length
As you know when velocity is calculated we can not take mass into account.
Answer:
v = 5.24[m/s]
Explanation:
Este problema se puede resolver por medio del principio de la conservación de la energía, donde la energía potencial es igual a la energía cinética. Es decir a medida que el carrito desciende su energía potencial disminuye, pero su energía cinética aumenta.

Donde:

Ahora reemplazando:
![\frac{1}{2} *m*v^{2}=m*g*h\\\\0.5*v^{2}=9.81*1.4\\v=\sqrt{\frac{9.81*1.4}{0.5} } \\\\v=5.24[m/s]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%3Dm%2Ag%2Ah%5C%5C%5C%5C0.5%2Av%5E%7B2%7D%3D9.81%2A1.4%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7B9.81%2A1.4%7D%7B0.5%7D%20%7D%20%20%20%5C%5C%5C%5Cv%3D5.24%5Bm%2Fs%5D)
The Atomic Number is equal to the amount of Protons and Electrons. To find the amount of Neutrons in an atom, you have to look at the Mass Number. The Mass Number is the SUM (_+_=_) of Protons and Neutrons in an atom. In this case, you will have to make up equations. For example: Argon. Argon's Mass Number is 40. You need to find the amount of Protons in the atom (18). Mass Number (40) - Protons (18) = Amount of Neutrons. 40-18=22.
Argon has 22 Neutrons, because Protons(18)+Neutrons(22)=Mass Number(40).
Hope I could help!