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

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.