I am pretty sure the answer is C.
Answer:

Explanation:
The heaviside function is defined as:

so we see that the Heaviside function "switches on" when
, and remains switched on when 
If we want our heaviside function to switch on when
, we need the argument to the heaviside function to be 0 when 
Thus we define a function f:

The
term inside the heaviside function makes sure to displace the function 5 units to the right.
Now we just need to add a scale up factor of 240 V, because thats the voltage applied after the heaviside function switches on. (
when
, so it becomes just a 1, which we can safely ignore.)
Therefore our final result is:

I have made a sketch for you, and added it as attachment.
Sorry bro I just need points for my calculus exam
Answer:
Speed: 109.4–120.7 km/h (68.0–75.0 mph)
Strength: Couldn't find out.
Explanation:
Answer:
a. Speed = 342.5 meters per seconds.
b. Wavelength = 2.0 meters
Explanation:
Given the following data;
Distance = 100m
Time = 292 milliseconds to seconds = 292/1000 = 0.292 seconds
Frequency = 171 Hz
a. To find the speed of sound in air;
Speed = distance/time
Speed = 100/0.292
Speed = 342.5 m/s
b. To find the wavelength;
Wavelength = speed/frequency
Wavelength = 342.5/171
Wavelength = 2.0 m