Answer:
Speed of the runner during video interval is 6.49 m/s
Step-by-step explanation:
According to the problem,
Number of frames recorded by camera in 1 second = 50
Time takes by camera to record 1 frame = (1/50) s
Time taken by camera to record 77 frames, t =
s
Distance covered by the runner during the video recording, d = 10 m
Speed, v =

Substitute the values of d and t in the above equation.
v =

v = 6.49 m/s