* 22. Mmh A car is traveling along a straight road at a velocity of 36.0 m/s when its engine cuts out. For the next twelve seconds the car slows down, and its average acceleration is For the next six seconds the car slows down further, and its average acceleration is The velocity of the car at the end of the eighteen-second period is 28.0 m/s. The ratio of the average acceleration values is Find the velocity of the car at the end of the initial twelve-second interval.

Complete question is;

A car is traveling along a straight road at a velocity of 36.0 m/s when its engine cuts out. For the next twelve seconds the car slows down, and its average acceleration is For the next six seconds the car slows down further, and its average acceleration is The velocity of the car at the end of the eighteen - second period is 28.0 m/s. The ratio of the average acceleration values is a1/a2 = 1.5.

Find the velocity of the car at the end of the initial twelve - second interval.

Your answer

30 m/s

Explanation:

To solve this, we will use Newton's first equation of motion;

v = u + at

Since we are dealing with acceleration ratio, let's make a the subject;

a = (v - u)/t

For the first 12 seconds and initial velocity u = 36 m/s, we have;

a1 = (v - 36)/12

For the remaining 6 seconds, initial velocity is the final velocity from the initial 12 seconds. Thus;

a2 = (28 - v)/6

We are given that a1/a2 = 1.5

Thus;

[(v - 36)/12]/[(28 - v)/6] = 1.5

(6/12)((v - 36)/(28 - v)) = 1.5

(v - 36)/(28 - v) = 1.5 × 12/6

(v - 36)/(28 - v) = 3

v - 36 = 3(28 - v)

v - 36 = 84 - 3v

4v = 120

v = 120/4

v = 30 m/s

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.