Question

The moon has a mass of 7.35 x 1022 kg and diameter of 3475 km. What is the gravitational field
strength on the surface of the moon? Give your answer in N kg! to three significant figures,
without units.​

Answer 1

Explanation:

The Attraction of Ceres Ceres, the largest asteroid known, has a mass of roughly

20 8.7 10 kg  . If Ceres passes within

14,000 km of the spaceship in which you are traveling, what force does it exert on you? (Use an approximate value for

your mass, and treat yourself and the asteroid as point objects.)

Picture the Problem: You and the asteroid attract each other gravitationally.

Strategy: Estimate that your

mass 70 kg.  Apply equation 12-1 to find the gravitational force between you and

Ceres.

Solution: Apply equation 12-1:

 

  

 

20

1 2 11 2 2

2 2 6

8.7 10 kg 70 kg

6.67 10 N m /kg 0.021 N

14 10 m

m m F G

r





    



Insight: If you stood on the surface of Ceres (radius 500 km) the force would be 16 N (3.6 lb).

Answer 2

Answer:

$F=1.624N*kg^{-1}$

Explanation:

As gravitational field strength formula is:
$F=\frac{GM*m}{r^{2} }$  and  $G=6.67*10^{-11} N*m^{2} *kg^{-2}$

Then:

$F=\frac{(6.67*10^{-11})*(7.35 * 1022) }{((3475/2)*1000m.))^{2} }$

After solving

$F=1.624N*kg^{-1}$