Explanation:
The orbital radius of the Earth is 
The orbital radius of the Mercury is 
The orbital radius of the Pluto is 
We need to find the time required for light to travel from the Sun to each of the three planets.
(a) For Sun -Earth,
Kepler's third law :

M is mass of sun, 
So,

(b) For Sun -Mercury,

(c) For Sun-Pluto,

Answer:
<u>Principal</u><u> </u><u>focus</u><u> </u><u>of</u><u> </u><u>concav</u><u>e</u><u> </u><u>lens</u><u> </u><u>-</u><u> </u>
★ The point at which rays parallel to principal axis coming from infinity appear to converge after being refracted from concave lens is called the principal focus of concave lens.
<em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em>
• <u>Additional</u><u> information</u><u> </u><u>-</u><u> </u>
★ Principal focus - A number of rays parallel to the principal axis after reflection from a concave mirror meet at a point on the principal axis or appear to come from a point after reflection from a convex mirror on the principal axis. This is called principal focus.
Gravity pulls to the centre of the earth. A ship floats in water because the water pushing it up (upthrust) is equal to the force<span> of gravity (weight) pulling it </span>down<span>. Friction also occurs when objects move through air. This is </span>called<span>air resistance.</span>
Answer:
Liquid has a defined volume but undefined shape
Explanation:
Explanation:
Solid has specific shape and volume
Liquid has specific volume but no specific shape
Gases have no specific volume and no specific shape
So correct answer is liquid.