Question

Using the equation given as,
$v=u+at$
Where $v$ be the final velocity, $u$ be the initial velocity, $a$ be the acceleration of the body and $t$ be the time taken. Using this equation, find out the time taken for the trip. It has been given that,
$\begin{align}
  & v=0m{{s}^{-1}} \\
 & u=-15m{{s}^{-1}} \\
 & a=2.5m{{s}^{-2}} \\
\end{align}$

Answer 1

Hint: Velocity is defined as the time rate of variation of the displacement of an object. The acceleration is defined as the time rate of variation of velocity. Substitute the values mentioned in the question in the equation which is also mentioned in the question. This will help you in answering this question.

Complete step by step answer:
First of all let us mention what all are given in the question. The initial velocity has been mentioned as,
$u=-15m{{s}^{-1}}$
The final velocity of the body can be written as per in the question,
$v=0m{{s}^{-1}}$
The acceleration of the body can be shown as,
$a=2.5m{{s}^{-2}}$
The newton’s first equation of motion can be written as,
$v=u+at$
Substituting the values in it will give,
$\Rightarrow 0=-15+2.5\times t$
Rearranging this equation in terms of time taken is needed. That is,
$\Rightarrow \dfrac{15}{2.5}=t$
Simplifying this will give the time taken in seconds. That is,
$\Rightarrow t=6s$
Therefore the time taken has been calculated.

Note:
Newton’s equations of motion are defined as the equations that explain the nature of a physical system as a function of time in terms of its motion. More clearly we can say that the equations of motion explains the nature of a physical system as a set of mathematical functions in terms of changing variables. Velocity and acceleration are vector quantities which are dependent on the magnitude as well as the direction of motion. Uniform acceleration means that the rate of variation in velocity with respect to the time taken will be a fixed value. This is the same as that of uniform velocity.