Wow! Very simple. Use the equation for momentum which is p=mv. You know your momentum and velocity, so do 120=m(4), now solve for m, which is 30. The mass of the child is 30 kg
Answer:
Explanation:
Given
Object fall from a height of 
Considering initial velocity to be zero i.e. 
using
where v=final velocity
u=initial velocity
a=acceleration
s=displacement


(b)Average acceleration
After falling 45 m, object strike the car and comes to rest after covering a distance of 0.5 m
again using

here final velocity will be zero i.e.
initial velocity 


(c)time taken by it to stop


Well as you've seen before most likely, an apple can fall right off a tree, and stay perfectly fine. its all dependent on the variables. What angle is the apple falling at? Whats the speed, height, even the size of the apple? We must take into aware anything can happen, but its all behind the variables.
Brainliest if helpful
P.S Fact Check with the second person who just answered
Gasses take the shape of their container.
A gas fills a container which takes both the shape and the volume of that container.