Science, asked by hardikn1683, 1 year ago

Explain briefly about rectilinear motion

Answers

Answered by Ajeet11111
1
Rectilinear motion is another name for straight-line motion. This type of motion describes the movement of a particle or a body. A body is said to experience rectilinear motion if any two particles of the body travel the same distance along two parallel straight lines.
Answered by rehanafirozsf
0
Rectilinear MotionRectilinear motion is another name for straight-line motion. This type of motion describes the movement of a particle or a body. 

A body is said to experience rectilinear motion if any two particles of the body travel the same distance along two parallel straight lines. The figures below illustrate rectilinear motion for a particle and body. 


Rectilinear motion for a particle: 

 


Rectilinear motion for a body: 

 


In the above figures, x(t) represents the position of the particles along the direction of motion, as a function of time t

Given the position of the particles, x(t), we can calculate the displacement, velocity, and acceleration. These are important quantities to consider when evaluating the kinematics of a problem. 

A common assumption, which applies to numerous problems involving rectilinear motion, is that acceleration is constant. With acceleration as constant we can derive equations for the position, displacement, and velocity of a particle, or body experiencing rectilinear motion. 

The easiest way to derive these equations is by using Calculus. 

The acceleration is given by 

 

where a is the acceleration, which we define as constant. 

Integrate the above equation with respect to time, to obtain velocity. This gives us 

 

where v(t) is the velocity and C1 is a constant. 

Integrate the above equation with respect to time, to obtain position. This gives us 

 

where x(t) is the position and C2 is a constant. 


The constants C1 and C2 are determined by the initial conditions at time t= 0. The initial conditions are: 

At time t = 0 the position is x1

At time t = 0 the velocity is v1

Substituting these two initial conditions into the above two equations we get 

 

Therefore C1 = v1 and C2 = x1


This gives us 

 


For convenience, set x(t) = x2 and v(t) = v2. As a result 

 


Displacement is defined as Δd = x2x1. Therefore, equation (1) becomes 

 


If we wish to find an equation that doesn’t involve time t we can combine equations (2) and (3) to eliminate time as a variable. This gives us 

 


Equations (1), (2), (3), and (4) fully describe the motion of particles, or bodies experiencing rectilinear (straight-line) motion, where acceleration a is constant. 

For the cases where acceleration is not constant, new expressions have to be derived for the position, displacement, and velocity of a particle. If the acceleration is known as a function of time, we can use Calculus to find the position, displacement, and velocity, in the same manner as before. 

Alternatively, if we are given the position x(t) as a function of time, we determine the velocity by differentiating x(t) once, and we determine the acceleration by differentiating x(t) twice. 

For example, let's say the position x(t) of a particle is given by 

 

Thus, the velocity v(t) is given by 

 

The acceleration a(t) is given by 

 
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