Answer:
11.47 m high
Explanation:
All of the Kinetic Energy converts to Potential energy
1/2 m v^2 = mgh divide both sides by 'm'
1/2 v^2 = gh (note that the masses given are irrelevant !)
(1/2 v^2) / g = h
(1/2 (15^2) / 9.81 = h = 11.47 m
Explanation :
There are many types of simple machines i.e. lever, wedge, pulley, wheel and axle etc.
Fulcrum is the pivot point about which the lever turns. When the position of the fulcrum is shifted, the position of effort changes.
There are three classes of the lever as class 1, class 2 and class 3.
Class 1 includes seesaws and scissors.
class 2 includes wheelbarrow
class 3 includes tongs and tweezers.
Insulators are the materials that are bad conductors of heat/electricity.insulation is tge pricess of covering any thing with such materials in order to prevent heat or electricity.
Answer:
The final velocity is 
Explanation:
From the question we are told that
The mass of the child is 
The initial speed of the child is 
The mass of the wagon is 
The initial speed of the wagon is 
The mass of the ball is 
The initial speed off the ball is 
Generally the initial speed of the system (i.e the child , wagon , ball) is

Generally from the law of linear momentum conservation

Here
is the momentum of the system before the ball is dropped which is mathematically represented as

=> 
=> 
and
is the momentum of the system after the ball is dropped which is mathematically represented as

=> 
So

=> 