We know that the electric field is equal to 1 E 6 V/m
The distance between the thundercloud and the ground is 1.6km = 1600m
Electric field = Voltage/distance
This means that the breakdown voltage must be equal to
V = 1 E 6 V/m * 1600m = 1.6 E 9 V = 1.6 GV
Answer:v=41.23 m/s
Explanation:
Given
mass of heavy object 
distance of
from the axle 
mass of rock 
Length of rod 
distance of
from axle 
Net torque acting is




Work done by
is converted to rock kinetic Energy
thus

Where 





Answer:
If this is a multiple choice question, then the answer is D.
Explanation:
Compounds are composed of atoms, which are composed of subatomic particles and consist of matter. Since they are composed of atoms rather than vice-versa, compounds cannot be found inside atoms and are not the most basic form of matter (ruling out A and C). A pure substance contains atoms, which are each composed of subatomic particles. Therefore, a pure substance must have atoms if it contains subatomic particles (ruling out B). The only answer left is D.