Mary is blowing up a birthday balloon.After the first breath, the balloon has a 5 cm diameter . the diameter increases at a constant rate of 20% each second. What is the diameter of the balloon after 3 seconds?
after 1st breath , diameter = 5cm
after 2nd breath , diamieter = 1.2(5) =
after 3rd breath, diameter = 5(1.2)^2=
The diameter of the balloon after 3 s is 8.64cm.
To find the diameter of the balloon after 3 seconds, we need to calculate the diameter at each second and then add up the changes.
Starting with the initial diameter of 5 cm, let's calculate the diameter at each second:
First second: The diameter increases by 20% from the initial diameter of 5 cm. To find the new diameter, we multiply 5 by 1.2 (20% increase is equivalent to multiplying by 1 + 0.2). The new diameter after the first second is 5 x 1.2 = 6 cm.
Second second: Again, the diameter increases by 20% from the previous diameter of 6 cm. Multiplying 6 by 1.2 gives us the new diameter of 6 x 1.2 = 7.2 cm.
Third second: Similarly, multiplying the diameter after the second second (7.2 cm) by 1.2 gives us the new diameter. So, 7.2 x 1.2 = 8.64 cm.
Therefore, after 3 seconds, the diameter of the balloon would be approximately 8.64 cm.
after 1st breath , diameter = 5cm
after 2nd breath , diamieter = 1.2(5) =
after 3rd breath, diameter = 5(1.2)^2=
(this question is physically unrealistic, Mary would be inserting the same amount of volume, which would show up with smaller and smaller increases in the diameter, certainly not a steady 20% increase each second)