Answer:
t = 2.2 s
Explanation:
Given that,
Height of the roof, h = 24.15 m
The initial velocity of the pumpkin, u = 0
We need to find the time taken for the pumpkin to hit the ground. Let the time be t. Using second equation of kinematics to find it as follows :

Here, u = 0 and a = g

So, it will take 2.22 s for the pumpkin to hit the ground.
Answer:
(a) The self inductance, L = 21.95 mH
(b) The energy stored, E = 4.84 J
(c) the time, t = 0.154 s
Explanation:
(a) Self inductance is calculated as;

where;
N is the number of turns = 1000 loops
μ is the permeability of free space = 4π x 10⁻⁷ H/m
l is the length of the inductor, = 45 cm = 0.45 m
A is the area of the inductor (given diameter = 10 cm = 0.1 m)

(b) The energy stored in the inductor when 21 A current ;

(c) time it can be turned off if the induced emf cannot exceed 3.0 V;

THIS IS NOT THE EXACT ANSWER BUT IT MIGHT HELP
The cover slips serves two purposes: (1) it protects the microscope's objective lens from contacting the specimen, and (2) it creates an even thickness (in wet mounts) for viewing.
The frequency of a sound wave is the number of cycles of a sound wave per second or Hertz (Hz). The frequency can be calculated by dividing wavelength by time (Figure 1.3). A small wavelength will yield a higher frequency, whereas a larger wavelength will yield a smaller frequency.