A ball is dropped from a height of 5m. After each bounce it rises to 35% of its previous height. After how many bounces does the ball reach a Height of less than 50cm?

Respuesta :

Answer:

After the third bounce the ball reaches a height of less than 50cm.

Step-by-step explanation:

Geometric sequence:

In a geometric sequence, the quotient between consecutive terms is always the same, and it's called common ratio. The nth term of a geometric sequence is given by:

[tex]A_n = A_0(r)^{n}[/tex]

In which [tex]A_0[/tex] is the first term and r is the common ratio.

A ball is dropped from a height of 5m.

This means that [tex]A_0 = 5[/tex]

After each bounce it rises to 35% of its previous height.

This means that [tex]r = 0.35[/tex]

Thus

[tex]A_n = A_0(r)^{n}[/tex]

[tex]A_n = 5(0.35)^{n}[/tex]

After how many bounces does the ball reach a Height of less than 50cm?

50cm = 0.5m. This is n for which [tex]A_n = 0.5[/tex]. Thus

[tex]A_n = 5(0.35)^{n}[/tex]

[tex]0.5 = 5(0.35)^{n}[/tex]

[tex](0.35)^n = \frac{0.5}{5}[/tex]

[tex](0.35)^n = 0.1[/tex]

[tex]\log{(0.35)^n} = \log{0.1}[/tex]

[tex]n\log{0.35} = \log{0.1}[/tex]

[tex]n = \frac{\log{0.1}}{\log{0.35}}[/tex]

[tex]n = 2.19[/tex]

Rounding up:

After the third bounce the ball reaches a height of less than 50cm.