Question

A rocket has a mass 250 x (10^3) slugs on earth. Specify(a) its mass in SI units, and(b)its weight in SI units.If the rocket is on the moon where the acceleration due to gravity is gm=5.30ft/s2, determine to three significant figures (c) its weight in SI units, and (d) its mass in SI units.

Answer 1

Explanation:

It is given that,

Mass of the rocket, $m=250\times 10^3\ slugs$

(a) The SI unit of mass is kilogram (kg). The relation between slugs and the kg is given by :

1 slug = 14.59 kg

So, $250\times 10^3\ slugs=250\times 10^3\times 14.59$

Mass of the rocket, m = 3647500 kg

(b) Weight of the rocket is given by :

W = m g

$W=3647500\times 9.8=35745500\ N$

or

$W=3.5\times 10^7\ N$

(c) If the rocket is placed on the moon. The acceleration due to gravity on the moon is, $a=5.3\ ft/s^2=1.61\ m/s^2$

Mass is the amount of matter contained inside the object. So, the mass of the rocket remains the same i.e. 3647500  kg

Weight of the rocket on the moon is, $W=mg$

$W=3647500\times 1.61$

W = 5872475 N

or

$W=5.8\times 10^6\ N$

Hence, this is the required solution.