Momentum is conserved if and only if sum of all forces which are exserted on system equals zero. In our situation there are only internal forces, so by Newton's third law their vector sum is 0.
So
.
Kinetic energy of system at first:
. After:
. The secret is that other energy is in work of deformation forces (they in turn heat a bullet and a block).
Answer is A)
Answer:
80 Ω.
Explanation:
In this circuit the resistances are in series.The equivalent resistance of a series circuit is equal to the sum of the resistances. Req= 60 + 20 = 80 Ω.
Answer: The current must be equal to
amps, or ~0.9574 amps.
Explanation:
You can find the current in amperes using ohms and watts from this formula:

Where P represents power in watts, R represents resistance in ohms, and I represents current in amperes.
You can then substitute 60 and 55 into the equation to find I:

Then, simplify the denominator:

Rationalize the denominator:

Simplify the numerator by finding its factors:

The current must be equal to
amps, or ~0.9574 amps.
Answer:
The atom is mostly empty space.
Explanation:
Ernest Rutherford in the year 1911 developed a model of an atom. In his model the atom was shown that the atom is mostly empty spaces composed of negative electrons which orbits round a positive nucleus just like planets revolving round the sun.
Rutherford came up with this model by performing experiments in 1909 which involves the scattering of alpha particles on a thin gold foil. From this experiments he came up with his model.