Answer:
Momentum is always conserved, and kinetic energy may be conserved.
Explanation:
For an object moving on a horizontal, frictionless surface which makes a glancing collision with another object initially at rest on the surface, the type of collision experienced by this objects can either be elastic or an inelastic collision depending on whether the object sticks together after collision or separates and move with a common velocity after collision.
If the body separates and move with a common velocity after collision, the collision is elastic but if they sticks together after collision, the collision is inelastic.
Either ways the momentum of the bodies are always conserved since they will always move with a common velocity after collision but their kinetic energy may or may not be conserved after collision, it all depends whether they separates or stick together after collision and since we are not told in question whether or not they separate, we can conclude that their kinetic energy "may" be conserved.
Answer:
The value is 
The force will be outward
Explanation:
From the question we are told that
The diameter of the disk is 
The external pressure on Mars is 
From the question we are told that
Internal pressure = External pressure
Generally the external Force on earth is
Here 
is the atmospheric pressure with value 
So
=> 
=> 
Generally the external Force on Mars is
=> 
=> 
Net force is mathematically represented as
=> 
=> 
converting to pounds
=>
Given that that the value is positive then the force will be outward
