Answer in the attachment.
Answer:
The answer to your question is 0.057 ha
Step-by-step explanation:
Data
Kilocalories needed for a person per day = 2450
Kilocalories produced per hectare = 15737000
Process
1.- Calculate the number of kcal needed per a person for a year
2450 kcal ----------------- 1 day
x ----------------- 365 days
x = (365 x 2450) / 1
x = 894250 kcal
2.- Calculate the amount of land needed
15737000 kcal ------------- 1 ha
894250 kcal ------------ x
x = (894250 x 1) / 15737000
x = 0.057 ha
After 1 hour, 360 g decays to 180 g.
After another hour (total 2 hours), 180 g decays to 90 g.
After another hour (total 3), 90 g decays to 45 g.
After one more (total 4), 45 g decays to 22.5 g.
More quickly, with a half-life of 1 hour, the 360 g of starting material decays to
(360 g) / 2⁴ = 22.5 g
In general, if the half-life is 1 hour, then after <em>n</em> hours, an initial amount <em>A</em> of this substance decays according to
<em>A</em> / 2<em>ⁿ</em>
Answer:
see explanation
Step-by-step explanation:
(a)
(the side required )² = sum of squares of other 2 sides - ( 2 × product of other 2 sides and cos(angle opposite side required ) )
x² = 12² + 15² - (2 × 12 × 15 × cos71°)
(b)
x² = 144 + 225 - 360cos71°
= 369 - 360cos71° ( take square root of both sides )
x = 
≈ 16 cm ( to the nearest integer )
