Answer:
Explanation:
To find the percentage of cars averaged less than 62 mph calculate the corresponding z-score and use a standard normal cumulative probability table
<u>1. Z-score</u>
![Z-score=\dfrac{x-\mu}{\sigma}](https://tex.z-dn.net/?f=Z-score%3D%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D)
- x is the specific value of the random variable: 62mph
- μ is the mean of the population: 65mph
- σ is the standard deviation of the population: 5mph
Substitute and calculate
![Z-score=\dfrac{62-65}{5}=-0.600](https://tex.z-dn.net/?f=Z-score%3D%5Cdfrac%7B62-65%7D%7B5%7D%3D-0.600)
<u>2. Use of the table.</u>
The percentage of cars that averaged less than 62mph is given by the area under the curve to the left of z = -0.600.
From a standard normal cumulative probability table, the probability of z being less than -0.600 (which is equal to the probability of z being greater than 0.600) is 0.2743, which is 27.43%.
Thus, the conclusion is that 27.43% of the cars averaged less than 62mph.
C. Particles stick to them
Neptune is mostly made of hydrogen.
t = t₀ / 2
Explanation:
In this exercise we must use Newton's second law
F = m a
a = F / m
now we can use kinematics
as in object part of rest (v₀ = 0)
v =a t₀
t₀ = v / a
these results are with the first experiment
now repeat the experiment, but F = 2F₀
a = 2F₀ / m = 2 a₀
v = 2 a₀ t
t = v / 2a₀
t = t₀ / 2