The best and most correct answer to the question is :
Alpha particles
Beta particles
Gamma rays
Cosmic radiation
Neutrons
Hope this helped you :)
Explanation:
a. Average speed = distance / time
= 100 m / 70 s
= 1.43 m/s
b. Average displacement = displacement / time
= 0 m / 70 s
= 0 m/s
Distance is the length of the path traveled. Displacement is the difference between the final position and initial position.
(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

It is in equilibrium if its velocity is not changing.