Joseph jogs from one end A to the other end B of a straight 300m road in 2 minutes 30 seconds and then turns around and jogs 100m back to point C in another 1 minute. What are Joseph's average speeds and velocities in jogging (a) from A to B (b) from A to C?
Answers
Distance from A to B = 300m
Displacement from A to B = 300m
Time taken to go from A to B = 2 min 50sec =170sec
a) Average speed in jogging from A to B = distance ÷ time
300m÷170sec = 1.76ms raised to power -1
Average velocity in jogging from A to B = displacement ÷ time
300m ÷170sec = 1.76ms
b) Distance covered from A to C = 300m +100m = 400m
Displacement from A to C = 300-100= 200
Time taken to go from A to C = 170 sec + 60s = 230s
Average speed from A to C = distance ÷time
400÷230= 1.74ms raised to power -1
Average velocity = displacement ÷ time
200÷230= 0.87 ms raised to power -1.
Answer:
Velocity = dispacement / time
Speed = distance / time
a) when he jogs from A to B on a straight road,
displacement = distance = 300m
time = 2 minutes 30 seconds = 150 s
velocity = 300/150 = 2 m/s
speed = 300/150 = 2m/s
b)when he jogs from A to B and turns back to C,
displacement = 300-100 = 200m
distance = 300+100 = 400m
time = 3 minute 30 second = 210 s
velocity = 200/210 = 20/21 m/s
speed = 400/210 = 40/21 m/s