<h3><u>Answer;</u></h3>
Large mirrors are easier to build than large lenses.
<h3><u>Explanation;</u></h3>
- <em><u>Reflector telescopes have a number of advantages as compared to refracting telescopes and other types of telescopes. </u></em>
- <em><u>Reflector telescopes do not suffer from chromatic aberration because all wavelengths will reflect off the mirror in the same way. The support for the objective mirror is all along the back side so they can be made very large.</u></em>
- Additionally, reflector telescopes are cheaper to make than refractors of the same size. Also since in reflector telescopes light is reflecting off the objective, rather than passing through it, only one side of the reflector telescope's objective needs to be perfect.
The complete sentence is:
A calorimeter directly measures changes in temperature in order to calculate specific heat.
In fact, the amount of energy acquired/released by a substance is directly proportional to its change in temperature due to the equation
where Q is the amount of energy, m is the mass of the substance, Cs is the specific heat of the substance and 
is the change in temperature. Therefore, by knowing Q, m and by measuring the change in temperature, it is possible to calculate Cs, the specific heat capacity of the substance.
Answer:
B.The box experiences less friction on the marble floor
Explanation:
G=?
m=7.35*10^22kg
r=1.74*10^6m
G=6.67*10^-11nm^2kg^-2
you can use the formula
g=Gm/r^2
450 J / 3 s = 150 J/s = 150 watts.
