Answer:
Area of the plates of a capacitor, A = 0.208 m²
Explanation:
It is given that,
Charge on the parallel plate capacitor, 
Electric field, E = 3.1 kV/mm = 3100000 V/m
The electric field of a parallel plates capacitor is given by :



A = 0.208 m²
So, the area of the plates of a capacitor is 0.208 m². Hence, this is the required solution.
-12 = 6.2*t - 4.9*t² → t = 2.32 sec (quadratic formula)
<span>V = Vi -g*t = 6.2 - 9.8*2.32 = -16.5 m/s</span>
Answer:
Option (c) is correct.
Explanation:
Acceleration of an object is given by the formula as follows :

Where
u and v are initial and final velocity
t is time
(v-u) is also called the change in velocity
So, the acceleration of an object is equal to the rate of change of velocity. Hence, the correct option is (c) " Change in its velocity divided by the change in time".
Answer:
B.
Explanation:
Given that a student runs up a flight of stairs which info is not needed to calculate the rate of the student is doing work against gravity A the height of the flight of stairs B the length of flight of stairs C the time taken to run up the stairs D the weight of the student
The rate of doing work is known as power.
Power = work done/time
Work done = energy = mgh
Since energy = mgh
Where mg = weight
And h = height
Time = time taken to run up the stairs.
Time, weight mg and height h will be needed while the Length of the flight is therefore not needed.
The correct answer is B.