DEFINITION:::::;;The type of reactions in which energy is releases to the environment are called Exothermic reactions.
EXAMPLE::: formation of carbon dioxide and urea formation are actually the examples of exothermic reaction..
Hope it helps
Answer:
Explanation:
Given
mass of book(m)=2.1 kg
height up to which book is lifted is (h)2.2 m
height of person 
Potential energy of book relative to ground=mgh

(b)PE w.r.t to person head =mg(h-h0)

work done by person in lifting box 2.2 m w.r.t floor
Word done =Potential Energy of box relative to floor=45.2 J
Answer:
<h3>75m</h3>
Explanation:
If a cat walk 100m East, this means that it is walking in the positive x direction, the distance will therefore be +100m
If it turns around and walks 25 m west, the direction of movement is in the negative x direction i.e -25m
Taking the sum;
Displacement = +100m - 25m
Displacement of the cat = 75m
hence the cats displacement is 75m
Answer:
A
Explanation:
I'm pretty sure it's A because when you look up the properties of alkali metal it states stuff about its melting points and what to expect. (correct me if I'm wrong but I had this same question on a test and I'm sure this is the answer lol)