Activity 2

Example 2.1

The motion of a particle in a plane is defined by
[tex]\[ x = 13 + 3t - 4 \][/tex]
[tex]\[ y = 12 - 2t + 6 \][/tex]
The units are in meters and seconds. Determine the velocity and acceleration after 3 seconds.



Answer :

Certainly! Let's solve this step-by-step based on the given problem.

### Problem Statement
The motion of a particle in a plane is defined by the equations:
[tex]$ x(t) = 13 + 3t - 4 $[/tex]
[tex]$ y(t) = 12 - 2t + 6 $[/tex]

We need to determine the velocity and acceleration of the particle after 3 seconds (t = 3 seconds).

### Step 1: Calculate the Position at t = 3 seconds
We need to determine the position of the particle at [tex]\( t = 3 \)[/tex] seconds using the given equations for [tex]\( x(t) \)[/tex] and [tex]\( y(t) \)[/tex].

#### For x(t):
[tex]$ x(3) = 13 + 3(3) - 4 $[/tex]
[tex]\[ = 13 + 9 - 4 \\ = 18 \][/tex]

#### For y(t):
[tex]$ y(3) = 12 - 2(3) + 6 $[/tex]
[tex]\[ = 12 - 6 + 6 \\ = 12 \][/tex]

So, the position of the particle at [tex]\( t = 3 \)[/tex] seconds is [tex]\( (18, 12) \)[/tex] meters.

### Step 2: Determine the Velocity
Velocity is the first derivative of the position with respect to time.

#### For x(t):
The velocity in the x-direction, [tex]\( v_x \)[/tex], is the derivative of [tex]\( x(t) \)[/tex]:
[tex]$ \frac{dx}{dt} = \frac{d}{dt}(13 + 3t - 4) \\ = 3 $[/tex]

#### For y(t):
The velocity in the y-direction, [tex]\( v_y \)[/tex], is the derivative of [tex]\( y(t) \)[/tex]:
[tex]$ \frac{dy}{dt} = \frac{d}{dt}(12 - 2t + 6) \\ = -2 $[/tex]

Therefore, the velocity of the particle at [tex]\( t = 3 \)[/tex] seconds is [tex]\( (3, -2) \)[/tex] meters per second.

### Step 3: Determine the Acceleration
Acceleration is the second derivative of the position with respect to time or the first derivative of velocity with respect to time.

#### For x(t):
The acceleration in the x-direction, [tex]\( a_x \)[/tex], is the derivative of [tex]\( v_x \)[/tex]:
[tex]$ \frac{d^2x}{dt^2} = \frac{d}{dt}(3) \\ = 0 $[/tex]

#### For y(t):
The acceleration in the y-direction, [tex]\( a_y \)[/tex], is the derivative of [tex]\( v_y \)[/tex]:
[tex]$ \frac{d^2y}{dt^2} = \frac{d}{dt}(-2) \\ = 0 $[/tex]

Therefore, the acceleration of the particle at [tex]\( t = 3 \)[/tex] seconds is [tex]\( (0, 0) \)[/tex] meters per second squared.

### Summary
- Position at [tex]\( t = 3 \)[/tex] seconds: [tex]\( (18, 12) \)[/tex] meters
- Velocity at [tex]\( t = 3 \)[/tex] seconds: [tex]\( (3, -2) \)[/tex] meters per second
- Acceleration at [tex]\( t = 3 \)[/tex] seconds: [tex]\( (0, 0) \)[/tex] meters per second squared