Answer:
2.9 M
Explanation:
The concentration-time equation for a second order reaction is:
1/[A] = kt + 1/[A°]
Where,
A = concentration remaining at time, t
A° = initial concentration
k = rate constant
1/[A] = (1.80 x 10^-3) * (45.6) + 1/3.81
1/[A] = 0.345
= 1/0.345
= 2.9 M.
The speed downwards is 7 + (3*9.8)
7+ 29.4 = 36.4 m/s
Basically, this problem asks you to convert kilocalories (kcal) to kilojoules (kJ). Both are units of energy. To convert kcal to kJ, the equivalence is: 1 kcal = 4.184 kJ. Through dimensional analysis, the solution is as follows:
750 kcal * 4.184 kJ/1 kcal = 3,138 kJ
Solar energy ....................