Answer:
Friction force always acts tangent to the surface at points of contact. Friction force acts opposite to the direction of motion. There are 2 types of friction: Static friction: If the two surfaces in contact do not move relative to each other, one has static friction.
1 and 4 are tire.
2 and 3 are not.
It's not true.
The crucial principle for a scientific experiment is to keep only ONE variable at a time.
In this case, the variable of this experiment is actually the tomato is in sunny part or in shady part, instead of whether applying Ca fertilizer.
Answer:

Explanation:
= Permittivity of free space = 
A = Area = 
d = Thickness = 
k = Dielectric constant = 5.4
V = Voltage = 86.2 mV
Charge is given by

The charge on the outer surface is 