For each of the following news stories, determine whether the objects speed or velocity is given: the world record for the hundred-meters dash is about 10m/s; the wind today is 30 km/h from the north-west; a 200,000 kg train was traveling north at 70 km/h when it derailed; a car was issued a ticket for traveling at 140 km/h on the interstate

the world record for the hundred-meters dash is about 10m/s - -> speed

the wind today is 30 km/h from the north-west - -> velocity

a 200,000 kg train was traveling north at 70 km/h when it derailed - -> velocity

a car was issued a ticket for traveling at 140 km/h on the interstate - -> speed

Explanation:

Let's remind the difference between speed and velocity first:

- The speed of an object is the ratio between the distance traveled by the object and the time taken. It is a scalar, so it has only a magnitude

- The velocity of an object is a vector whose magnitude is equal to the ratio between the displacement of the object and the time taken, and a direction given by the direction of motion. So, velocity has both magnitude and direction.

Let's analyze now each option:

the world record for the hundred-meters dash is about 10m/s - -> this has only a magnitude (10 m/s), so it is a speed

the wind today is 30 km/h from the north-west - -> this has both a magnitude (30 km/h) and a direction (north-west), so it is a velocity

a 200,000 kg train was traveling north at 70 km/h when it derailed - -> this has both magnitude (70 km/h) and direction (north), so it is a velocity

a car was issued a ticket for traveling at 140 km/h on the interstate - -> this has only a magnitude (140 km/h), so it is a speed