Answer:
The center of mass of three mass in the x-y plane is located at (1,0.5).
Explanation:
It is given that, a mass of 6 kg is at (0,0), a mass of 4 kg is at (3,0), and a mass of 2 kg is at (0,3). We need to find the center of mass of the system. Center of mass in x direction is :

The center of mass in y direction is :

So, the center of mass of three mass in the x-y plane is located at (1,0.5).
Answer:
60,000m
Explanation:
Convert km/h to m/s by multiplying with 1000/3600.
Convert hours to seconds by multiplying with 3600.
Because displacement is a vector quantity and deals with the shortest distance between points, simply plug it into the equation s=vt.
Answer:

3257806.62409 m/s
Explanation:
G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²
M = Mass of Sun = 
r = Radius of Star = 20 km
u = Initial velocity = 0
v = Final velocity
s = Displacement = 16 m
a = Acceleration
Gravitational acceleration is given by

The gravitational acceleration at the surface of such a star is 

The velocity of the object would be 3257806.62409 m/s