$A$ person travels along a straight road for the first half time with a velocity $v_1$ and the next half time with a velocity $v_2$. The mean velocity $V$ of the man is

Define speed. Define average speed.

$A$ person walks along a straight road from his house to a market $2.5 \,km$ away with a speed of $5 \,km/h$ and instantly turns back and reaches his house with a speed of $7.5 \,km/h$. The average speed of the person during the time interval $0$ to $50 \,min$ is (in $m/s$)

Which information cannot be drawn from average velocity?

$A$ vehicle runs on a straight road of length $L$. It travels half the distance with speed $V$ and the remaining distance with speed $\frac{V}{3}$. Its average speed is

$A$ particle travels half of the distance of a straight journey with a speed $6 \,m/s$. The remaining part of the distance is covered with speed $2 \,m/s$ for half of the time of the remaining journey and with speed $4 \,m/s$ for the other half of the time. The average speed of the particle is ....... $m/s$.