Answer:
t = 2 hours
Explanation:
Given that,
Distance of the town, d = 90 miles
Speed, v = 45 mph
We need to find the time to get there. The speed of an object is given by :

Where
t is time

So, the required time is 2 hours.
Average speed = total distance traveled/total time taken
it is the total distance traveled in a total time the total distance is attained
Answer:
1.1299 x 10^-8 second
Explanation:
Period = 1 / f = 1 / (8.85 * 10^7) = 1.1299 x 01^-8 sec
Understand future consequences, for tell the future, control urges, and delayed gratification
Answer: D(t) = 
Explanation: A harmonic motion of a spring can be modeled by a sinusoidal function, which, in general, is of the form:
y =
or y = 
where:
|a| is initil displacement
is period
For a Damped Harmonic Motion, i.e., when the spring doesn't bounce up and down forever, equations for displacement is:
or 
For this question in particular, initial displacement is maximum at 8cm, so it is used the cosine function:
period =
12 =
ω = 
Replacing values:

The equation of displacement, D(t), of a spring with damping factor is
.