Answer: 9 days
Explanation:
Let the rate of Leaf growth <em>r</em> be defined as,
= 
where <em>A</em> is initial area of the leaf, <em>A1</em> is the final area of the leaf and<em> t</em> is the time taken for the increase in Area.
- Express the proportional relationship in equation.
Given that rate of leaf growth, r is proportional to the surface area of the leaf A. we have r ∝ A.
r = kA, where k is the rate constant.
therefore, k = 
when A = 2
, A1 = 3
so k = 
=
÷ 2
= 0.33 ÷ 2
k = 0.167
- After calculating the rate constant k, we then find the time t when A1 is 5

- we have r = k × A1 =

so, 0.167 × 2 = 
0.33 =
.
t = 3/0.33
Therefore, t = 9 days.
A boiling pot of water (the water travels in a current throughout the pot), a hot air balloon (hot air rises, making the balloon rise) , and cup of a steaming, hot liquid (hot air rises, creating steam) are all situations where convection occurs.
Answer:
r₂=0.1 m
Explanation:
Given that
r₁= 10 m , β₁ = 20 dB
At r₂ ,β₂= 60 dB
As we know that intensity level of sound given as



10² x 10⁻¹² = I₁
I₁=10⁻¹⁰ W/m²


10⁶ x 10⁻¹² = I₂
I₂ = 10⁻⁶ W/m²
I₁=10⁻¹⁰ W/m²
P = I A
P=Power ,I =Intensity ,A=Area


r₂=0.1 m