Answer:
It will take the boulder approximately 4.28 seconds to hit the road
Step-by-step explanation:
The given height of the cliff from which the boulder falls, h = 90 feet
The equation that can be used to find the time it takes the boulder to fall is h = u·t + (1/2)·g·t²
Where;
h = The height of the cliff = 90 ft.
u = The initial velocity of the boulder = 0 m/s (The boulder is assumed to be at rest when it falls)
g - The acceleration due to gravity ≈ 9.81 m/s²
t = How long it will take for the boulder to hit the road below
Plugging in the values gives;
90 = 0 × t + (1/2)×9.81×t² = 4.905·t²
∴ t = √(90/4.905) ≈ 4.28
The time it takes the boulder to hit the road, t ≈ 4.28 seconds.
Answer:
(a) 0.5899
(b) 0.9166
Step-by-step explanation:
Let X be the random variable that represents the height of a woman. Then, X is normally distributed with
= 62.5 in
= 2.2 in
the normal probability density function is given by
, then
(a)
= 0.5899
(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2)
(b) We are seeking
where n = 37.
is normally distributed with mean 62.5 in and standard deviation
. So, the probability density function is given by
, and
= 0.9166
(in the R statistical programming language) pnorm(63, mean = 62.5, sd = 2.2/sqrt(37))
You can use a table from a book to find the probabilities or a programming language like the R statistical programming language.