(a) 764.4 N
The weight of the astronaut on Earth is given by:

where
m is the astronaut's mass
g is the acceleration due to gravity
Here we have
m = 78.0 kg
g = 9.8 m/s^2 at the Earth's surface
So the weight of the astronaut is

(b) 21.1 N
The spacecraft is located at a distance of

from the center of Earth.
The acceleration due to gravity at a generic distance r from the Earth's center is

where G is the gravitational constant and M is the Earth's mass.
We know that at a distance of r = R (at the Earth's surface) the value of g is 9.8 m/s^2, so we can write:
(1)
the acceleration due to gravity at r=6R instead will be

And substituting (1) into this formula,

So the weight of the astronaut at the spacecratf location is

Answer:
6.29 m
Explanation:
The speed of a wave is equal to frequency times wavelength, so to find wavelength you'd have to divide frequency by both sides, speed(346) divided frequency(55) = 6.29 m
I'm not so sure about this let me know if I'm wrong
Answer : C. Pascal's principle.
Explaination : Pascal's principle (well-known as Pascal's law) states that if a closed container contains a fluid at rest, then a small change in pressure at one side of the fluid is transmitted to each and every part of the fluid and also to the walls of the container without any loss. In a hydraulic lift, we need the same mechanism to work and so we take the help of Pascal's principle.
Hence, the correct option is C. Pascal's principle.
The block is ACCELERATING to the left, but there's not enough information to tell which direction it's moving.