Answer:
Tina's overall average speed for the journey is 56 km/h.
Step-by-step explanation:
Sean's travel time from Town A to Town B is 4 hours.
Sean's average speed is 70 km/h.
Using the motion equation, s = ut + 0.5 at², we can find:
Time, t = 4 hours.
Initial speed, u = 70 km/hr.
Acceleration, a = 0 m/s².
Replacing the variables:
s = ut + 0.5 at²
s = 70 x 4 + 0.5 x 0 x 4²
s = 280 km
The distance from Town A to Town B is 280 km.
Tina's travel time exceeds Sean's by 1 hour.
Tina's time to travel from Town A to Town B is 4 + 1 = 5 hours.
Again applying the motion equation, s = ut + 0.5 at²:
Time, t = 5 hours.
Distance, s = 280 km.
Acceleration, a = 0 m/s².
Putting in values:
s = ut + 0.5 at²
280 = u x 5 + 0.5 x 0 x 5²
u = 56 km/hr.
Tina's overall average speed is thus 56 km/h.
