Question

a ball rolling on a ground covers a distance of 200m fue south in 20s. What is the speed of the ball? What is its velocity​

[ans. 10 metre per second, 10 metre per second due south]

Answer 1

Answer:

10 m/s , 10m/s due south

Explanation:

DISTANCE - 200m

TIME - 20sec

Speed = Distance ÷ Time

= 200 ÷ 20

= 10 m/s

As we know , Speed = velocity

so, the velocity is 10 m/s due south.

Answer 2

SPEED IS 10 m/s & VELOCITY IS 10 m/s due south.

Given:

• Ball rolls 200 metres towards south in 20 seconds.

To find:

Speed & Velocity of the ball ?

Calculation:

Speed is a scalar quantity which is defined as the total distance divided by the total time. Speed only has magnitude and no direction.

$speed = \dfrac{distance}{time}$

$\implies speed = \dfrac{200}{20}$

$\implies speed = 10 \: m {s}^{ - 1}$

So, speed is 10 m/s.

However, velocity is a vector quantity defined as the total displacement divided by the total time. So, both magnitude and the direction has to be mentioned in case of velocity.

$velocity = \dfrac{displacement}{time}$

$\implies velocity = \dfrac{200}{20}$

$\implies velocity = 10 \: m {s}^{ - 1}$

So, velocity is 10 m/s towards south.