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Is Matter Around Us Pure

Question
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A bullet of mass 10 g moving with a velocity of 400 m/s gets embedded in a freely suspended wooden block of mass 900 g. What is the velocity acquired by the block?

Solution

Let the final velocity of the bag along with the bullet embedded in it be v.
therefore space space For space bullet colon thin space m subscript 1 space equals space 10 space straight g space equals space 0.01 space kg semicolon space space straight u subscript 1 space equals space 400 space straight m divided by straight s semicolon space space straight v subscript 1 space equals space straight v space straight m divided by straight s

space space space space space space For space bag colon space space space space straight m subscript 2 space equals space 900 space straight g space equals space 0.9 space kg semicolon space space straight u subscript 2 space equals space 0 semicolon space space space straight v subscript 2 space equals straight v space straight m divided by straight s
Now, According to the law of conservation of momentum,
Total momentum before collision = Total momentum after collision
That is, 
space space space space space space space space space space space space space space space space straight m subscript 1 straight u subscript 1 space plus space straight m subscript 2 straight u subscript 2 space equals space straight m subscript 1 straight v subscript 1 plus straight m subscript 2 straight v subscript 2

rightwards double arrow space space space space space space space space space space space space straight m subscript 1 straight u subscript 1 plus space straight m subscript 2 straight u subscript 2 space equals space left parenthesis straight m subscript 1 plus straight m subscript 2 right parenthesis straight v space space space space space space space space space space open square brackets because space space straight v subscript 1 space equals straight v subscript 2 space equals space straight v close square brackets

rightwards double arrow space space space space space space space space space space space space space space space space space space space straight v space equals space fraction numerator straight m subscript 1 straight u subscript 1 plus straight m subscript 2 straight u subscript 2 over denominator straight m subscript 1 plus straight m subscript 2 end fraction

space space space space space space space space space space space space space space space space space space space space space space space space space space space equals fraction numerator 0.01 space cross times 400 space plus 0.9 space cross times 0 over denominator 0.01 space plus 0.9 end fraction
space space space space space space space space space space space space space space space space space space space space space space space space space space space equals fraction numerator 4 over denominator 0.91 end fraction

space space space space space space space space space space space space space space space space space space space space space space space space space space equals 400 over 91 equals 4.4 space straight m divided by straight s.

Some More Questions From Is Matter Around Us Pure Chapter

Which separation techniques will you apply for the separation of the following?

Wheat grains from husk

Which separation techniques will you apply for the separation of the following?


Fine mud particles suspended in water.

Write the steps you would use for making tea. Use the words—solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?

Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66



Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66


What is the effect of change of temperature on the solubility of a salt?

Explain the following giving examples:

Saturated solution

Explain the following giving examples:

Pure substance

Explain the following giving examples:


Colloid