The momentum of a body of given mass is proportional to its

$A$ body can have zero average velocity but not zero average speed. Justify this statement by giving an example.

What is the relationship between the distance travelled and the time elapsed for motion with uniform velocity?

Distinguish between speed and velocity.

Which of the following is not a vector?

The average time taken by a normal person to react to an emergency is $1/15$ of a second and is called the 'reaction time'. If a bus is moving with a velocity of $60 \, km/h$ and its driver sees a child running across the road,how much distance would the bus have moved before he could press the brakes? The reaction time of the people increases when they are intoxicated. How much distance would the bus have moved if the reaction time of the driver were $1/2 \, s$ under the influence of alcohol?