Question

A car initially travelling north at 5m/s has a constant of 2m/s northward how far the car travels in the first 10s?

Answer 1

Hint: The statement “has a constant of 2m/s northward” means that velocity is increasing at a fixed rate of 2m/s i.e. acceleration of the body is given as $2m/{s^2}$. Use the equation of motion to calculate distance.

Complete step-by-step answer:
Step1: Writing down what is given and what is needed to calculate.
Given that, initial velocity $u = 5m/s$
                     Acceleration $a = 2m/{s^2}$
                                   Time $t = 10s$
                         Distance travelled $S = ?$
Step2: Use the equation of motion to calculate the distance travelled,
$S = ut + \dfrac{1}{2}a{t^2}$
Substitute all the values in above equation to calculate the distance
$S = 5 \times 10 + \dfrac{1}{2} \times 2 \times {10^2}$
Step3: Now simplifying the above equation to calculate the distance,
$
  S = 5 \times 10 + \dfrac{1}{2} \times 2 \times {10^2} \\
  S = 50 + 100 \\
   \Rightarrow S = 150m \\
$
So the distance traveled by the body in the first 10 seconds is 150m.

Note: Always remember that the rate of change of velocity is acceleration. Sometimes in questions instead of acceleration directly they write the rate at which velocity is changed.