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
Answers
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
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