Answer:
The velocity of the leaf relative to the jogger is 5 m/s.
Explanation:
Given that,
Velocity of jogger wrt to the ground, 
velocity of leaf wrt the ground, 
We need to find the velocity of the leaf relative to the jogger. Let it is equal to V. So, it is given by :

So, the velocity of the leaf relative to the jogger is 5 m/s. Hence, this is the required solution.
NaCl is a compound formed by a chemical reaction between Na (Sodium) and Cl (Chlorine). Sodium is an alkai metal in Group One of the Periodic Table, and it is very reactive. All alkai metals react violently with water and they are often found combined in nature because they are that reactive. Chlorine is a halogen in Group 17 of the Periodic Table and they are very reactive.
A.) reference group
"A reference group includes individuals or groups that influence our opinions, beliefs, attitudes and behaviors. They often serve as our role models and inspiration"(study.com).
Mass movement is the movement of surface materials caused by gravity. A great example would be a mud slide.