Ballistic pendulum conservation of momentum/mechanical energy?

"Mechanical energy and momentum are conserved only when certain conditions rae met. Explain why the collision between the ball and the pendulum conserves momentum but not mechanical energy. Similarly, explain why the motion of the pendulum during its swing conserves mechanical energy but (apparently) not momentum."

I understand why during the collision kinetic energy is lost and momentum is conserved, but why would mechanical energy be conserving during the swing and not momentum?

9. an object is moved from the outdoors, which is at a temperature of 100 ºf, to a room at a temperature of 70 º f. what happens to the object when it’s placed in the room with a lower temperature? the object gives off more energy than it absorbs until it reaches a new lower thermal equilibrium where the amount of energy absorbed and given off is the same. the object gives off the same amount of energy as it absorbs until it reaches a new lower thermal equilibrium where the amount of energy given off is greater than the amount of energy it absorbs. the object gives off more energy than it absorbs until it reaches a new higher thermal equilibrium where the amount of energy absorbed and given off is the same. the object absorbs more energy than it gives off until it reaches a new lower thermal equilibrium where the amount of energy absorbed and given off is the same.