Answer:
10000 V
0.00225988700565 m²

Explanation:
E = Electric field = 
d = Gap = 2.5 mm
Q = Charge = 80 nC
= Permittivity of free space = 
Potential difference is given by

The potential difference between the plates is 10000 V
Area is given by

The area of the plate is 0.00225988700565 m²
Capacitance is given by

The capacitance is 
A roller coaster is stopped on a track. When the engineer presses a launch button on the coaster, the coaster moves forward. Explain this change in terms of balanced and unbalanced forces.
when object goes under acceleration
c).its velocity always increases
<h3><u>Additional</u><u> </u><u>information</u><u>:</u><u>-</u></h3>
★ Acceleration: Rate of increase in velocity.
★ Velocity: Distance travelled by a body per unit time in given direction is called velocity .
Answer:
Explanation:
When a body is held against a vertical wall , to keep them in balanced position , normal force is applied on their surface . this force creates normal reaction which acts against the normal force and it is equal to the normal force as per newton's third law . Ultimately friction force is created which is proportional to normal force and it acts in vertically upward direction . It prevents the body from falling down .
Hence normal force = reaction force .
From second law also net force is zero , so if normal force is N and reaction force is R
R - N = mass x acceleration = mass x 0 = 0
R = N .
Ranking normal force from highest to smallest
150 N , 130 N , 120 N
B )
Frictional force is equal to the weight of the body because the body is held at rest .
Ranking of frictional force form largest to smallest
7 kg , 5 kg , 3 kg , 1 kg .
Here frictional force is irrespective of the normal force acting on the body because frictional force adjusts itself so that it becomes equal to weight in all cases here because it always balances the weight of the body .