Question

A 10.0 kg mass is at the origin. A 20.0

kg mass is 0.500 m to the left of it,
and a 30.0 kg mass is 1.25 m to the
right of it. What is the net gravitational
force on the 10.0 kg mass?

Answer 1

to the left

Step-by-step explanation:

The gravitational force exerted between two objects is given by

were

G is the gravitational constant

m1, m2 are the masses of the two objects

r is their separation

And the force is always attractive.

Let's call

the mass on which we are calculating the net force.

The mass on the left is

and it is a distance of

r = 0.500 m

So, the gravitational force exerted by this mass on the 10.0 kg mass is

And the direction is to the left.

The other mass is

and its distance is

r = 1.25 m

to the right, so the force exerted by this other mass on the 10.0 kg mass is

And the direction is to the right.

Now, to find the net force, we just have to calculate the algebraic sum, taking into account that the two forces have different directions; taking right as a positive direction, the net force is:

And the negative sign means the direction of the net force is to the left.