Question

A car moves eastwards with a speed of 50 km/h. It crosses another car travelling westwards with a speed of 50 km/h.
(a) Do they have same speed? ​

Answer 1

Answer:

no i don't think they have the same speed

Answer 2

Answer:

Yes !!

Explanation:

We generally represent objects moving in a particular direction in terms of velocity. Velocity and speed are two different things. We will see how.

Let take our east direction as +ve and

west direction as -ve.

Velocity of car moving eastwards = + 50 km/h

Velocity of car moving westwards = - 50 km/h

Both velocities are different.

Note: The changes in sign shows the direction in which they are moving. Velocity gives us the complete information.

When we talk about speed, it is just the magnitude of velocity, no sign nothing.

Speed of car moving eastward = 50 km/h

Speed of car moving westward = 50 km/h

Note: If we write just 50 km/h it doesn't tell us anything about direction. So, both car will have same speed but different velocities.

In your classes when you will learn about vector quantities it will be more fun. Go research about vectors , you will truly appreciate it.