The acceleration of an object (in [tex]$m / s^2$[/tex]) is given by the function [tex]$a(t) = 7 \sin(t)$[/tex]. The initial velocity of the object is [tex][tex]$v(0) = -13 \, m/s$[/tex][/tex]. Round your answers to four decimal places.

a) Find an equation [tex]$v(t)$[/tex] for the object's velocity.
[tex]\[
v(t) = -7 \cos(t) - 6
\][/tex]

b) Find the object's displacement (in meters) from time 0 to time 3.
[tex]\[
\text{Displacement} = -18.9877 \, \text{meters}
\][/tex]

c) Find the total distance traveled by the object from time 0 to time 3.
[tex]\[
\text{Total distance traveled} = \square \, \text{meters}
\][/tex]



Answer :

Let's break down each part of the problem and solve it step-by-step.

### Part (a) Find an equation [tex]\( v(t) \)[/tex] for the object velocity.

We are given the acceleration [tex]\( a(t) = 7 \sin(t) \)[/tex]. The acceleration is the derivative of velocity, i.e., [tex]\( v'(t) = a(t) \)[/tex].

To find the velocity [tex]\( v(t) \)[/tex], we need to integrate the acceleration function.
[tex]\[ v(t) = \int 7 \sin(t) \, dt \][/tex]

The integral of [tex]\( 7 \sin(t) \)[/tex] is:
[tex]\[ v(t) = -7 \cos(t) + C \][/tex]

To determine the constant [tex]\( C \)[/tex], we use the initial condition [tex]\( v(0) = -13 \)[/tex]:
[tex]\[ v(0) = -7 \cos(0) + C = -13 \][/tex]

Since [tex]\( \cos(0) = 1 \)[/tex], we can solve for [tex]\( C \)[/tex]:
[tex]\[ -7 \cdot 1 + C = -13 \][/tex]
[tex]\[ -7 + C = -13 \][/tex]
[tex]\[ C = -6 \][/tex]

Thus, the velocity function is:
[tex]\[ v(t) = -7 \cos(t) - 6 \][/tex]

### Part (b) Find the object's displacement from time 0 to time 3.

Displacement is the integral of velocity over the given time interval [0, 3].

[tex]\[ \text{Displacement} = \int_{0}^{3} v(t) \, dt \][/tex]

Using the velocity function [tex]\( v(t) = -7 \cos(t) - 6 \)[/tex]:

[tex]\[ \text{Displacement} = \int_{0}^{3} (-7 \cos(t) - 6) \, dt \][/tex]

After performing this integration, we obtain:
[tex]\[ \text{Displacement} = -18.9878 \, \text{meters} \][/tex]

### Part (c) Find the total distance traveled by the object from time 0 to time 3.

The total distance traveled is the integral of the absolute value of the velocity function over the given time interval [0, 3].

[tex]\[ \text{Total Distance} = \int_{0}^{3} |v(t)| \, dt \][/tex]

Using the velocity function [tex]\( v(t) = -7 \cos(t) - 6 \)[/tex], we compute:

[tex]\[ \text{Total Distance} = \int_{0}^{3} | -7 \cos(t) - 6 | \, dt \][/tex]

After performing this integration, we obtain:
[tex]\[ \text{Total Distance} = 19.4292 \, \text{meters} \][/tex]

### Summary of Results
(b) The object's displacement from time 0 to time 3 is:
[tex]\[ -18.9878 \, \text{meters} \][/tex]

(c) The total distance traveled by the object from time 0 to time 3 is:
[tex]\[ 19.4292 \, \text{meters} \][/tex]