Question

billy pushes his little brother on a sled through the snow. he then tries to push his father on the the same sled. he noticed that it was much harder to push his father. which law is this an example of? 1st law 3rd law 2nd law

Explanation:

Newton's 2nd Law states that force ($F$) equals mass ($m$) times acceleration ($a$), $F = ma$. When pushing the sled, the father has more mass than the brother. To achieve the same acceleration (or start moving the sled), a greater force is needed for the more massive father, which matches the observation that it's harder to push the father. The 1st Law is about inertia (objects at rest/motion stay that way unless force acts), and the 3rd Law is about action - reaction pairs, neither of which fit this scenario.

Answer:

2nd Law