If my math is right its A) 7
because 189 divided by 27 is 7
Answer:
The tangential velocity of a rotating object is:
v = r*w
where r is the radius, and w is the angular velocity.
w = 2*pi*f
where f is the frequency.
We know that the record plater does 11 revolutions in 20 seconds, then it does:
11 rev/20s = 0.55 rev/s = f
then we have:
w = 2*pi*0.55 s^-1 = 2*3.14*0.55 s^-1 = 3.454 s^-1
The radius of a record player is really variable, it is around 10 inches, so i will use r = 10in, which is the rotating part of the record player.
then the tangential velocity is:
v = 10in*3.454 s^-1 = 34.54 in/s
Answer: A method of classifying stars by their temperatures and compositions.
Explanation:
Answer:
if they are the same temperature
Explanation:
Answer:
a.
The hypothesis Null and alternative can be formulate as a :
H0 = μ = 7.5 hr / week
Hₐ = μ < 7.5 hr / week
b.
The Null hypothesis is true and the administrator believes that the college freshman dot not spend 7.5 hours
E(x) = μ = 7.5 hr / week
SE (x) = σ / √ n = 9 / √100
SE (x) = 0.9
Z' = 6.6 - 7.5 / SE
Z' = 6.6 -7.5 / 0.9 = -1
The empirical rule in this case is use
% = (100 - 68 ) / 2 = 16%
c.
There is not strong arguments of Null Hypothesis so can be accept the H0 and is no significantly different from the report of 7.5 hr / week
