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Given the velocity and initial position of a body moving along a coordinate line at time t, find the bodys position at time t.

V = 8/pi sin 4t/pi, s(pi^2) = 2
1. s = -2 cos 4t/pi + 3
2. s = -2 cos 4t/pi + 4
3. s = -2 cos 4t/pi + 8
4. s = -2 cos 4t/pi + 4

User Joymaker
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2 Answers

3 votes

Final answer:

To find the body's position at time t given the velocity function and initial position, we integrate the velocity function with respect to t and solve for the constant of integration using the initial position. The resulting position function is s = -2*cos(4t/pi) + 4.

Step-by-step explanation:

To find the body's position at time t, we need to integrate the velocity function. In this case, the velocity function is V = 8/pi * sin(4t/pi). We can integrate this function with respect to t to obtain the position function, s. The antiderivative of sin(4t/pi) is -2*cos(4t/pi). Therefore, the position function is s = -2*cos(4t/pi) + C, where C is the constant of integration.

Given that s(pi^2) = 2, we can substitute t = pi^2 into the position function and solve for C. 2 = -2*cos(4(pi^2)/pi) + C. Simplifying this equation gives C = 4.

Therefore, the body's position at time t is s = -2*cos(4t/pi) + 4.

User Veshraj Joshi
by
5.9k points
4 votes

Answer:

4. s = -2 cos 4t/pi + 4

Step-by-step explanation:

The position is the integral of the velocity.

In this question:


v(t) = (8)/(\pi)\sin{((4t)/(\pi))}

So


s(t) = \int {v(t)} dt


s(t) = \int {(8)/(\pi)\sin{((4t)/(\pi))}} dt

Integrating by substitution:


u = (4t)/(\pi)


du = (4)/(\pi)dt


dt = (\pi du)/(4)

So


s = \int {(8)/(\pi)sin(u) ((\pi du)/(4))


s = 2 \int {sin(u)} du


s = -2 cos(u) + C

Since
u = (4t)/(\pi)


s(t) = -2 \cos{(4t)/(\pi)} + C

Since s(pi^2) = 2 .


s(t) = -2 \cos{(4t)/(\pi)} + C


2 = -2 \cos{(4\pi^(2))/(\pi)} + C


2 = -2cos(4\pi) + C

The cosine of 4pi is the same as the cosine of 0 = 1. So


2 = -2 + C


C = 4

So the correct answer is:

4. s = -2 cos 4t/pi + 4

User Michael Washington
by
4.6k points
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