Answer:
1.38*10^18 kg
Explanation:
According to the Newton's law of universal gravitation:

where:
G= Gravitational constant (6.674×10−11 N · (m/kg)2)
ma= mass of the astronaut
mp= mass of the planet

so:

B. Electrons are negative so one single 1 would be negative 1
Answer:
The value is 
Explanation:
From the question we are told that
The time taken to travel to the planet from earth is 
The time to be spent on the ship is
Generally speed can be obtained using the mathematical relation represented below

The 2 in the equation show that the trip is a round trip i.e going and coming back
=> 
=> 
The answer is C I believe