Answer:
Explanation:
Between two spheres of equal masses having equal radius , the one which is hollow will have less moment of inertia and therefore less radius of gyration ( k )
When they are allowed to roll over an inclined plane , they will have acceleration as follows
a = gsinθ / ( 1 + k²/r²)
For hollow sphere , k is less . therefore denominator is less and acceleration is more.
in other words , hollow sphere will have greater acceleration . So it will reach the bottom of an inclined surface in lesser time if allowed to roll over it .
This is how we can identify a hollow sphere without breaking it open .
Refer to the diagram shown below.
Let m = the mass (g) of the door.
Let v = the launch velocity
Let u = the velocity of the door after impact.
Elastic impact (rubber ball):
The rubber ball bounces off the door with presumably elastic impact, which means that both momentum and kinetic energy are conserved.
Conservation of momentum requires that
400v = -400v + mu
Therefore

Inelastic impact (clay):
The clay sticks to the door after impact.
Conservation of momentum requires that
400g = (m+400)u
Therefore

When we compare magnitudes of u for the door, we find that

Clearly, the elastic impact creates a greater value of u for the door.
Answer:
The rubber ball creates a larger impulse to the door because the nature of its impact is approximately elastic.
Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood:

Salt water:

Silver:

Lead:

<span>We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.</span>
The change in temperature is simply 50 / (9/5) = 27.777. We just throw out the 32 from the formula
Answer: S2P6
The electronic configuraiton of given elements are as follows:
Ne =<span><span><span>[<span>He</span><span>]2</span></span><span>s2 2</span><span>p6<span>
</span></span></span>Ar = </span><span><span><span>[<span>Ne</span><span>]3</span></span><span>s2 3</span><span>p6<span>
</span></span></span>Kr = </span><span><span>[<span>Ar</span><span>]4</span></span><span>s2 3</span><span>d10 4</span>p6</span>
As it can be seen that for all three elements, their outermost orbital are completely filled, that is it has both s orbital, p orbital and d orbital fulfilled. Noble or inert gas atoms like Neon, Argon, Krypton have fulfilled valence shell. Fulfilled outermost orbital is the most stable electronic state, hence all elements tends to achieve such stability. These noble gas elements are called inert gas because of their fulfilled outermost shell. This means they don't react easily or take part in eletron donating, receiving or sharing. This is because, for all other elements except inert gas atoms, their valence shell is incomplete and they tend to react by other atoms so as to complete their outermost shell , which we call as duplet (in case of Helium like) or Octet state. Such elements either donate some electrons or receive some to acheive such stable state..