A particle moves along the sides $AB, BC, CD$ of a square of side $25 \,m$ with a velocity of $15$$m{s^{ - 1}}.$ Its average velocity is........$m{s^{ - 1}}$

Velocity of an object in rectilinear motion is given as function of time by $v = t -t^3$, where $v$ is in $m/s$ and $t$ is in seconds. Its average velocity over the time interval from $t = 0\ s$ to $t = 2\ s$ is........$m/s$

The average velocity of a body moving with uniform acceleration travelling a distance of $3.06\, m$ is $ 0.34 ms^{-1}$. If the change in velocity of the body is $ 0.18ms^{-1}$ during this time, its uniform acceleration is.........$ms^{-2}$

A man walks on a straight road from his home to a market $2.5\; km$ away with a speed of $5 \;km h ^{-1} .$ Finding the market closed, he instantly turns and walks back home with a speed of $7.5 \;km h ^{-1} .$ What is the average speed of the man over the interval of time $0$ to $40\; min$ ?

A horse rider covers half the distance with $5\,m / s$ speed. The remaining part of the distance was travelled with speed $10\,m / s$ for half the time and with speed $15 m / s$ for other half of the time. The mean speed of the rider averaged over the whole time of motion is $\frac{x}{7}\,m / s$. The value of $x$ is

Which among average speed and average velocity can be positive, negative or zero ?