+91-8076753736[email protected]
logo
logo
-->

Atoms And Molecules

Question
CBSEENSC9006100
Wired Faculty App

The mass of the earth is 6 x 1024 kg and that of the moon is 7.4 x 1022 kg. If the distance between the earth and the moon be 3.84 x 105 km, calculate the force exerted by the earth on the moon. The value of G = 6.7 x 10–11 Nm2 kg–2.

Solution

Given semicolon space space The space mass space of space the space earth comma space straight M space equals space 6 space cross times space 10 to the power of 24 kg space The space space mass space of space the space moon comma space straight m space equals space 7.4 space cross times space 10 to the power of 22 kg 
The distance between the earth and the moon is, 
                    r = 3.84 x 105 m
                      = 3.84 x 105 x 1000 m
                      = 3.84 x 108 m
The value of G = 6.7 x 10-11 Nm2 kg-2

The force exerted by the earth on the moon is, 

straight F space equals space straight G Mm over straight r squared space equals fraction numerator 6.7 space cross times space 10 to the power of negative 11 end exponent cross times 6 space cross times space 10 to the power of 24 space cross times space 7.4 space cross times 10 to the power of 22 over denominator left parenthesis 3.84 space cross times space 10 to the power of 8 right parenthesis squared end fraction equals 2.01 space cross times space 10 to the power of 20 straight N 

Thus the force exerted by the earth on the moon is 2.01 x 1020 N. 

Some More Questions From Atoms And Molecules Chapter

When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen ? Which law of chemical combination will govern your answer?

What are polyatomic ions? Give examples.

Write the chemical formulae of the following:

(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate 
(d) Aluminium chloride
(e) Calcium carbonate

Give the names of the elements in the following compounds.

(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder 
(d) Potassium sulphate.

Calculate the molar mass of the following substances:

(a) Ethylene
(b) Sulphur molecule, S8
(c) Phosphorus molecule, P4
(d) Hydrochloric acid, HCl
(e) Nitric acid, HNO3.

What is the mass of:

(a) 1 mole of nitrogen atoms

(b) 4 moles of aluminium atoms

(c) 10 moles of sodium sulphite.

Convert into mole

(a) 12 gm of oxygen gas

(b) 20 gm of water

(c) 22 gm of carbon dioxide.

What is the mass of?

(a) 0.2 mole oxygen atoms.

(b) 0.5 mole of water molecules.

Calculate the number of molecules of sulphur (S8) present in 16 gm of solid sulphur.

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation