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
All living organisms need energy grow and reproduce maintain their structures, and respond to their enviorments: metabolism is the set of the processes that make energy available for cellular processes.
Answer:
steam will have the lowest density.
Hope it will help :)
To solve the problem it is necessary to apply the concepts related to thermal expansion of solids. Thermodynamically the expansion is given by

Where,
Original Length of the bar
= Change in temperature
= Coefficient of thermal expansion
On the other hand our values are given as,




Replacing we have,



The width of the expansion of the cracks between the slabs is 0.5832cm