Answer:
Robert Hooke
Was the first to use the word "cell"
Observed cork cells
Anton van Leeuwenhoek
Observed "animalcules"
Used polished lens
.
Explanation:
Anton van Leeuwenhoek is known as father of microbiology. He is credited to improve the quality of lens in microscope. His first observation of organisms called animalcules.
He is credited to have build microscope that could get magnified by 200 times. He used word animalcules for small organisms from pond water when first observed in microscope. He discovered protozoa and named it animalcules".
Robert Hooke is famed for discovering cell from a cork of plant. He observed a compartment or honey comb like divisions when observed these cork cells under the microscope and named it cell. He was only able to see the cell wall as the cork cells are dead cells.
Answer:
a) t=10.2s
b) The 2g-cube moves first
Explanation:
Since the electric force is the same on both cubes and so is the coefficient of static friction, the first one to move will be the one with less mass.
So, on the 2g-cube the sum of forces are:

Replacing the friction on the first equation:
Thus 
The electric force is:
Solving for q:
q=71.44nC
This amount divided by the rate at which they are being charged:
t = 71.44nC / 7nC/s = 10.2s
Answer:
Hydrogen has one electron and one proton
Answer:
Explanation:
coefficient of kinetic friction of wooden floor μ = .4
force of friction = μ R , R is reaction force of floor
R = mg = weight of body
R = 25 N
force of friction = .4 x 25 = 10 N
Net force on the crate = 10 - 10 = zero .
Net force on the body will be nil.
Answer:
If they are metallic spheres they are connected to earth and a charged body approaches
non- metallic (insulating) spheres in this case are charged by rubbing
Explanation:
For fillers, there are two fundamental methods, depending on the type of material.
If they are metallic spheres, they are connected to earth and a charged body approaches, this induces a charge of opposite sign and of equal magnitude, then it removes the contact to earth and the sphere is charged.
If the non- metallic (insulating) spheres in this case are charged by rubbing with some material or touching with another charged material, in this case the sphere takes half the charge and when separated each sphere has half the charge and with equal sign.