Answer:
Catapult on the ground: Normal, gravity
Catapult (I'm assuming launching marshmallow): Reaction of Force Applied
Marshmallow: Force Applied
Explanation:
This is the forces that act on a stationary object and a launched object. The catapult may also experience a force friction if your teacher is taking a more practical sense.
Answer:
distance= 10 km
displacement= 7.21 km
Explanation:
distance= scalar (only magnitude)
displacement= vector (magnitude & direction)
distance= 6 km+ 4 km
= 10 km
displacement= shortest difference btwn 2 pts=
sqrt( 6^2+4^2)
sqrt(52)
7.21 km
The question is missing, however, I guess the problem is asking for the value of the force acting between the two balls.
The Coulomb force between the two balls is:

where

is the Coulomb's constant,

is the intensity of the two charges, and

is the distance between them.
Substituting these numbers into the equation, we get

The force is repulsive, because the charges have same sign and so they repel each other.