The solution for this problem is:
Let x = speed of wind
Speed of plane with the wind = x + 100
Speed of plane against the wind = 100 -x
We will be using the formula for distance which is (Rate)(Time), getting the formula for time would be distance/rate Time to travel 600 miles with the wind = Time to travel 400 miles against the wind 600/(x + 100) = 400/(100 - x)
400(x + 100) = 600(100 - x)
400x + 40000 = 60000 - 600x
1000x = 20000
x = 20000/1000
x = 20 mph
A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Remembering that
d = m ÷ v
d = ?
m = 89 g
v = 10 cm³
Therefore:
d = 89 ÷ 10
d = 8,9 g÷cm³