Answer: A.The moon doesn’t have an atmosphere to burn up the rocks before hitting the surface.
Explanation:
Unlike the Earth, the Moon does not have an atmosphere, this leads to at least to facts:
1) Since the atmosphere (in the case of Earth) is mainly composed of gases (including oxigen) that can make combustion; when a meteor enters in the atmosphere and gets in contact with oxigen it becomes flamable and part of it is burned and separated. Then, if the meteor was large enough, the parts that were not separated will impact on the Earth Surface.
In the Moon, meteors completely impact the surface.
2) In our planet, after the meteorite impact, the crater formed will gradually fade due to erosion caused by the atmosphere. In the case of the Moon, the craters remain intact, since there is not erosion on its surface.
Answer:
The momentum of the bale the moment it strikes the ground is 1076.68 kg-m/s.
Explanation:
It is given that,
Velocity of an animal-rescue plane, 
It drops a bale of hay from an altitude of 69 m, h = 69 m
The vertical velocity of plane is given by :


Weight of the bale of hay, W = 192 N
If m is the mass, then weight is given by :


The resultant momentum of the bale the moment it strikes the ground is given by :



Magnitude of momentum,

p = 1076.68 kg-m/s
So, the momentum of the bale the moment it strikes the ground is 1076.68 kg-m/s. Hence, this is the required solution.
Answer:0 N-m
Explanation:
Given
Force applied is given by 
It is given that there is no movement of car
therefore Net displacement is zero i.e. 
Work done is given by




No, the skydiver does not start moving upward. Yes, initially the air drag is stronger than the weight, and so there is a net force pushing upward, and the result of this force (because of F=ma) is a deceleration of the skydiver (because the force goes against the direction of motion). However, the air drag is proportional to

, the square of the velocity. Thus, as the velocity of the skydiver decreases, so does the air drag, and eventually the air drag becomes smaller than the weight. So the skydiver continues his motion towards the ground.