Velocity
Because velocity is speed with direction. In this scenario, the speed has not changed, but the direction did.
Options:
(a) Total kinetic energy of the system remains constant.
(b) Total momentum of the system is conserved.
(c) Both A and B are true.
(d) Neither A nor B are true.
Answer:
(b) Total momentum of the system is conserved.
Explanation:
An inelastic collision is a type of collision in which momentum is conserved and kinetic energy is not conserved. That is, there is loss of kinetic energy.
In an inelastic collision:
Total momentum before collision = Total momentum after collision
An example of inelastic collision is seen in the ballistic pendulum, The ballistic pendulum is a device in which a projectile such as a bullet is fired into a suspended heavy wooden stationary block.
Answer: 
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,
where,
= initial pressure of gas at STP = 1 atm
= final pressure of gas = 2.67 atm
= initial volume of gas =
= final volume of gas = ?
= initial temperature of gas at STP =
= final temperature of gas =
Now put all the given values in the above equation, we get:

Thus the final volume will be 
A.Positive as work=force×distance (assuming that distance is always a constant) the work will always be positive as the force is always positive(this is because force=mass×acceleration where the acceleration is always positive unless the mass is being slowed down)