Answer:
f = 5 cm
Explanation:
using the thin lens equation, given as follows:

where,
f = focal length = ?
do = the distance of object from lens = 20 cm
di = the distance of image from lens = 6.6667 cm
Therefore,

<u>f = 5 cm</u>
The answer is a.12.5kg because i just did the test and it was correct.
hope this helps
Answer:
1703.24J
Explanation:
Given parameters:
Mass of brick = 7.9kg
Height of building = 22m
Unknown:
Potential energy of the brick = ?
Solution:
The potential energy of a body is the energy at rest of the body. Mathematically;
P.E = mgh
m is the mass of the brick
g is the acceleration due to gravity
h is the height of the building
Insert the given parameters and solve;
P.E = 7.9 x 9.8 x 22 = 1703.24J
Answer:Science is valued by society because the application of scientific knowledge helps to satisfy many basic human needs and improve living standards. Finding a cure for cancer and a clean form of energy are just two topical examples.
Explanation:
<h3>
Answer: 104.5 cubic cm</h3>
=======================================================
Work Shown:
r = radius = 1.045 cm
h = height = 30.48 cm
pi = 3.141 approximately
V = volume of cylinder
V = pi*r^2*h
V = 3.141*(1.045)^2*30.48
V = 104.547940002
V = 104.5 cubic cm