The atomic number for an element whose mass number is 115, which contains 66 neutrons per atom is: 49
The formula and procedure we will use to solve this problem is:
Information about the problem:
Applying the number of protons formula we get:
number of protons = mass number - number of neutrons
number of protons = 115 - 66
number of protons = 49
Applying the atomic number formula we get:
atomic number =number of protons
atomic number = 49
<h3>What is an atom?</h3>The atom is the smallest part of the composition of matter, it is indivisible and is composed of a nucleus that has protons and neutrons, and around the nucleus there are the electrons.
Learn more about the atom at: brainly.com/question/17545314
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The work done in lifting the hamburger is equal to the increase in gravitational potential energy of the hamburger, given by
where
m=0.1 kg is the mass of the hamburger
is the gravitational acceleration
is the increase in height of the hamburger
Substituting numbers into the equation, we find
So, the correct answer is
(3) 0.3 J
Answer:
<em>a) 318.2 W/m^2</em>
<em>b) 2.5 x 10^-4 J</em>
<em>c) 1.55 x 10^-8 v/m</em>
<em></em>
Explanation:
Power of laser P = 1 mW = 1 x 10^-3 W
exposure time t = 250 ms = 250 x 10^-3 s
If beam diameter = 2 mm = 2 x 10^-3 m
then
cross-sectional area of beam A = = (3.142 x
)/4
A = 3.142 x 10^-6 m^2
a) Intensity I = P/A
where P is the power of the laser
A is the cros-sectional area of the beam
I = ( 1 x 10^-3)/(3.142 x 10^-6) = <em>318.2 W/m^2</em>
<em></em>
b) Total energy delivered E = Pt
where P is the power of the beam
t is the exposure time
E = 1 x 10^-3 x 250 x 10^-3 = <em>2.5 x 10^-4 J</em>
<em></em>
c) The peak electric field is given as
E =
where I is the intensity of the beam
E is the electric field
c is the speed of light = 3 x 10^8 m/s
= 8.85 x 10^9 m kg s^-2 A^-2
E = = <em>1.55 x 10^-8 v/m</em>