Answer:
20 J
Explanation:
Given:
Weight of the book is, 
Height or displacement of the book is, 
The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.
So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.
Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.
Therefore, work done is given as:

Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.
Answer:
The gain in velocity is 0.37m/s
Explanation:
We need solve this problem though the conservation of momentum. That is,


Using the equation to find
,

Using the conservation of energy equation, we have,




Now this energy over the cannonball



The gain in velocity is 0.37m/s
The channel is whatever was used to carry information from
one place to another, or from one person to another.
In this scenario, the channel is e-mail.
B is the correct answer since acid corrode on metals such as carbon, steel, zinc and such.
Answer:
<h2>3.3 J</h2>
Explanation:
The potential energy of a body can be found by using the formula
PE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 10 m/s²
From the question we have
PE = 1.5 × 10 × 0.22
We have the final answer as
<h3>3.3 J</h3>
Hope this helps you