Answer:
Rusting of irons
Change in molecular composition
irreversible change
Explanation:
chemical change Is an irreversible change so we will only observe permanent change
Answer:
625 piece.
Explanation:
Let n be the required no of piece
200 litre = 200 x 10⁻³ m³ = 200 x 10⁻³ x 10³ kg = 200 Kg
mass of ice piece = n x 30 x /1000
Heat lost by ice pieces = (n x 30) / 1000 x ( 80 + 1 x 16⁰C)
Heat gained by water = 200 x 1 x 9⁰C
Heat lost = Heat gained
(n x 30) /1000 x ( 80 + 16 ) =200 x 9
2.88 n = 1800
n = 625
Answer:
Correct answer: 11. Total distance d = 200m ; 12. Vav = 3.63m/s ;
13. Total displacement Dt = 0m ; 14. V₂(10s-15s) = 0 m/s ;
15. V₃(15s-40s) = 4 m/s ; 16. V₁(0s-10s) = 6 m/s > V₄(40s-55s) = 2.67 m/s
Explanation:
The whole movement can be divided into four stages.
In the first stage the subject moves 60m in a positive direction for 10s,
in the other it is stationary for 5s, in the third it moves 100m in the opposite (negative) direction for 25s and in the fourth in the positive 40m for 15s.
11. Total distance = 60 + 0 + 100 + 40 = 200m
12. The formula for calculating the average speed (velocity) is
Vav = (S₁ + S₂ + S₃ + S₄) / (t₁ + t₂ + t₃ + t₄)
Vav = (60 + 0 + 100 + 40)/ (10 + 5 + 25 + 15) = 200/55 = 3.63 m/s
13. The movement started from the origin and ended at the origin
Total displacement is zero meters.
14. The speed between 10s and 15s is zero, because he did not move.
15. V₃ = S₃/t₃ = 100/25 = 4 m/s
16. V₁ = S₁/t₁ = 60/10 = 6 m/s and V₄ = S₄/t₄ = 40/15 = 2.67 m/s
V₁ > V₄
God is with you!!!