Answer:
220.7
Explanation:
distance traveled is 1.5*5=7.5m
PE gain is MGH=3*9.81*7.5=220.7
Energy=mass*SHC*temp change
=100*0.9*75
=6750J
Answer:
16
Explanation:
The magnitude of the electrostatic force between two charged particles is given by

where
k is the Coulomb's constant
q1, q2 are the charges of the two particles
r is the separation between the particles
In this problem, the initial force between the particles is F.
Later, the distance between the two particles is increased by four, so
r' = 4r
So, the new force between the particles will be

So, the new force decreases by a factor of 16.
Answer:
The illumination on the book before the lamp is moved is 9 times the illumination after the lamp is moved.
Explanation:
The distance of the book before the lamp is moved, 
The distance of the book after the lamp is moved, 
Illumination can be given by the formula, 
Illumination before the lamp is moved, 
Illumination after the lamp is moved, 



The illumination on the book before the lamp is moved is 9 times the illumination after the lamp is moved.