Answer:
a) 30.82 m/s
b) 183.33 Hz
Explanation:
a)
V = speed of the sound = 339 m/s
v = speed of the train = ?
f' = observed frequency by the observer = 220 Hz
f = actual frequency of the observer = 200 Hz
using the equation


v = 30.82 m/s
b)
V = speed of the sound = 339 m/s
v = speed of the train = 30.82 m/s
f'' = observed frequency by the observer as train moves away = ?
f = actual frequency of the observer = 200 Hz
using the equation


f'' = 183.33 Hz
Answer:
The correct option is b) By the time they get to be theories, they cannot be disproven. It's not necessary that the theories are always right. They can be proven wrong.
Explanation:
Answer: The center of gravity is 1.1338 m away from the left side of the barbell
Explanation:
Length of the barbell = 1.90 m
The distance center of gravity from left = x
Mass on the left side = 25 kg
The distance center of gravity from right = 1.90 - x
Mass on the right side = 37 kg
At the balance point: 


The center of gravity is 1.1338 m away from the left side of the barbell
The answer is 21 that is it