Answer:
Explanation:
Given
initially steam is at
and converted to
ice
Let m be the mass of steam
latent heat of fusion and vaporization for water is


Heat required to convert steam in to water at 

Heat required to lower water temperature to 



Heat required to convert
water to ice at
is





So this energy is equal to kinetic energy of bullet of mass m moving with velocity v




Answer:
The radius of the gold nucleus is 7.1x10⁻¹⁵m
Explanation:
The nearest distance is:
(eq. 1)
Where
z = atomic number of gold = 79
e = electron charge = 1.6x10⁻¹⁹C
k = electrostatic constant = 9x10⁹Nm²C²
energy of the particle = 32 MeV = 5.12x10⁻¹²J
At the potential energy is zero, all the energy will be kinetic energy:

Where
m = 4 mp = mass of proton

Replacing in equation 1

Answer:
The amount of electrons that flow in the given time is 3.0 C.
Explanation:
An electric current is defined as the ratio of the quantity of charge flowing through a conductor to the time taken.
i.e I =
...................(1)
It is measure in Amperes and can be measured in the laboratory by the use of an ammeter.
In the given question, I = 1.5A, t = 2s, find Q.
From equation 1,
Q = I × t
= 1.5 × 2
= 3.0 Coulombs
The amount of electrons that flow in the given time is 3.0 C.
The final mass after decay can be obtained by using under given relation:
half life period of As-81 = 33 seconds
mf = mi x (1/2^n)
= 100 x ( 1/2^(43.2/33))
= 40.4 %