Answer:
12 weeks
Step-by-step explanation:
Step one:
given data
let the heights of the plants be y
and the number of weeks be x
Plant A
y=3x+8.5--------------1
Plant B
y=2.5x+14.5----------2
Required
The number of weeks taken for both plants to have the same height
,equate the two expressions above
3x+8.5=2.5x+14.5
3x-2.5x=14.5-8.5
0.5x= 6
divide both sides by 0.5
x= 6/0.5
x= 12 weeks
Answer:
ρ_air = 0.15544 kg/m^3
Step-by-step explanation:
Solution:-
- The deflated ball ( no air ) initially weighs:
m1 = 0.615 kg
- The air is pumped into the ball and weight again. The new reading of the ball's weight is:
m2 = 0.624 kg
- The amount of air ( mass of air ) pumped into the ball can be determined from simple arithmetic between inflated and deflated weights of the ball.
m_air = Δm = m2 - m1
m_air = 0.624 - 0.615
m_air = 0.009 kg
- We are to assume that the inflated ball takes a shape of a perfect sphere with radius r = 0.24 m. The volume of the inflated ( air filled ) ball can be determined using the volume of sphere formula:
V_air = 4*π*r^3 / 3
V_air = 4*π*0.24^3 / 3
V_air = 0.05790 m^3
- The density of air ( ρ_air ) is the ratio of mass of air and the volume occupied by air. Expressed as follows:
ρ_air = m_air / V_air
ρ_air = 0.009 / 0.05790
Answer: ρ_air = 0.15544 kg/m^3
Answer:
Step-by-step explanation:
(2b+-7)+5(b+-3)
Multiply 5 throughout the second parentheses
(2b-7)+(5b-15)
Add 2b and 5b
7b-7-15
Subtract -7 and -15
7b-22