Answer:
B.The charge on A is -q; there is no charge on B.
Explanation:
We are given that
Charge=+q
We have to find the correct statement.
When positive charge is placed at center of uncharged metal sphere
insulated from the ground then negative charge(-q) induced on inner
surface A of sphere and the outer surface B is grounded then the surface is neutral .
It means there is no charge on surface B.
Hence, option B is true .
B.The charge on A is -q; there is no charge on B.
Answer:
6.216 N
Explanation:
As for Newton's second law of motion
F=ma
where F= the acting force
m=subjected mass
a= the acceleration
applying F=ma to the football
F=m*a
=0.42*14.8
=6.216 N
6.216 N of a force is supplied to the ball
Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,

where;
the threshold of hearing 



I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A
rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W
The third one sliding friction
Explanation: