Question

A body moving along a straight line Travels one third of Total distance with a speed of 3 metres per second the remaining distance is covered with a speed of 4 metre per second for half the time and 5 M per second for the other half of the time the average speed during the motion is

Answer 1

hope this is enough to understand

Answer 2

Answer:

The average speed will be $\bold{\frac{27}{7} \mathrm{m} / \mathrm{s}}$

Explanation:

Let the total distance be “x”.

So $\frac{1}{3} \mathrm{x}=3 \mathrm{m} / \mathrm{s}$

$T1 = \frac{x}{9} Remaining distance = \frac{2}{3} x$

Given for half the time the remaining distance is covered with speed $\frac{t 2}{2}=4 \mathrm{m} / \mathrm{s}$

Hence Distance$\mathrm{x} 1=\frac{4 t 2}{2}$

For second half of distance to be covered speed is $\frac{t 2}{2}$ = 5 m/s

So Distance $\mathrm{x} 2=\frac{5 t 2}{2}$

$\begin{array}{l}{\mathrm{X} 1+\mathrm{x} 2=\frac{2}{3} \mathrm{x}} \\ {\rightarrow \frac{9}{2} \mathrm{t} 2=\frac{2}{3} \mathrm{x}} \\ {\rightarrow \mathrm{t} 2=\frac{4}{27} \mathrm{x}}\end{array}$

Average speed = $\frac{x}{t 1+t 2}=\frac{x}{\frac{x}{9}+\frac{4}{27} x}=\frac{27}{7} \mathrm{m} / \mathrm{s}$