Question

If a girl runs around a circular track of length 400m and comes back to
the initial point in 40s, what would be her speed and velocity.
7 point
O speed 25m/s,velocity 10
O speed 29m/s, velocity o
speed 10m/s, velocity 0
O speed 10m/s, velocity 10​

Answer 1

AnSwer :-

➠ Given :

• Length of circular path = 400m
• Girl comes to the initial position after 40s.

➠ To Find :

• Speed
• Velocity

➠ Concept :

➨ Speed is defined as the ratio of total distance travelled to the total time taken.

➨ Velocity is defined as the ratio of displacement to the time.

➨ Distance is defined as the actual length of path which is covered by moving body (scalar).

➨ Displacement is defined as the shortest distance b/w initial and final position of entire journey (vector).

➠ Calculation :

⟿ Speed of Girl :

⇒ Speed = Distace/time

⇒ Speed = 400/40

⇒ Speed = 10m/s

⟿ Velocity of Girl :

⟶ Here, Displacement of girl will be zero because she comes to the initial position after the given interval of time.

➢ Velocity = Displacement/time

➢ Velocity = 0/40

➢ Velocity = 0 m/s

Answer 2

The girl runs around a circular track of length 400m and comes back to initial point

Now Displacement = Shortest distance is initial and final position

Since the girl returned to the initial position

So Displacement = 0

Now

Velocity = Displacement / Time = 0 /40 = 0

Speed of Girl = Distance / time = 400/40 = 10 m/s