On the surface of the Mars, gravity is 3.8 m/s2 . An astronaut has a mass of 90 kg. (a) Calculate his weight on Earth, (b) State his mass when on Mars and (c) calculate his weight when on Mars.

(a) W = 882 N

(b) m = 90 kg

(c) Wm = 342 N

Explanation:

(a)

The weight of n object on the surface of earth is given as:

W = mg

where,

W = Weight of Astronaut on Earth = ?

m = mass of astronaut = 90 kg

g = acceleration due to gravity on surface of earth = 9.8 m/s²

Therefore,

W = (90 kg)(9.8 m/s²)

W = 882 N

(b)

Mass of a body is a universal constant. The mass of the body remains same any where in the universe. Therefore, on mars the mass of astronaut will be:

m = 90 kg

(c)

The weight of an object on the surface of Mars is given as:

Wm = m(gm)

where,

Wm = Weight of Astronaut on Mars = ?

m = mass of astronaut = 90 kg

gm = acceleration due to gravity on surface of Mars = 3.8 m/s²

Therefore,

Wm = (90 kg)(3.8 m/s²)

Wm = 342 N