Blood pressure, wind, plant tissues and humidity
Answers are for parents and teachers.
1
Air holds 4.5 g of vapour per m³ and could hold 18 g. Find the relative humidity.
4.5 ÷ 18 × 100 = 25%.
2
Place P has 998 mbar and place Q has 1006 mbar. Which way does the wind blow?
From Q to P.
3
Write a blood pressure of 125/85 mmHg in words and find the difference between the two numbers.
125 over 85; the difference is 125 − 85 = 40 mmHg.
4
Name the three plant tissues and give one job of each.
Parenchyma: storage; collenchyma: flexible strength; sclerenchyma: rigid strength.
5
Explain why sweat cools the body only when it evaporates.
Evaporation takes heat from the skin.