Question

A particle moves for 20 sec with velocity 3 m/s and then moves with 4 m/s for
another 20 sec and finally moves with velocity 5 m/s for next20 sec. What is the
average velocity of the particle?
A.3m/s
B.4m/s
C.5m/s
D.0

Answer 1

Hint: The average velocity of an item is its complete relocation separated by the all-out time taken. As such, it is the rate at which an item changes its situation, starting with one spot then onto the next. Average velocity is a vector amount.

Complete answer:
The SI unit is in meters for every second. Be that as it may, any separation unit per whenever unit can be utilized when vital, for example, miles every hour (mph) or kilometer every hour (kmph).
As we know that the initial velocity is 3 m/s
The given time is = 20sec
\[d={{v}_{1}}{{t}_{1}}+{{v}_{2}}{{t}_{2}}+{{v}_{3}}{{t}_{3}}\]
\[\because {{t}_{1}}={{t}_{2}}={{t}_{3}}=20sec\]
\[T=~3\times 20~=60sec.\]
\[\begin{align}
  & v=\dfrac{d}{t}\,=\dfrac{240}{60}\,=4~m/s \\
 & \\
\end{align}\]
There is frequently disarray over the contrast between average speed and the average velocity. Be that as it may, in the realm of Physics, speed and velocity are two unmistakably various substances. Speed is a scalar amount, while the velocity is a vector amount. As a result, it implies that speed doesn't require a bearing, yet velocity needs the course.
It is sufficient to state that the speed of an object states, 25 m/s however then again, the articulation for the velocity of a similar article will be 25 m/s, east (or some other course).

The correct answer is B.

Note:
The minus sign indicates the average velocity is also toward the rear of the plane. The average speed of an object is defined as the distance traveled divided by the time elapsed. Velocity is a vector quantity, and the average velocity can be defined as the displacement divided by per unit of the time.