Answer:
Anna drove at an average speed of 49.73 km/h
Step-by-step explanation:
Average Speed
If an object moves at different speeds to cover a certain total distance dt in a total time tt, the average speed is:
[tex]\displaystyle \bar v=\frac{d_t}{t_t}[/tex]
Anna drives a total distance of dt=45 km each day. One day she drives a distance of d1=25 km at v1=82 Km/h. The time taken for that distance is:
[tex]\displaystyle t_1=\frac{d_1}{v_1}=\frac{25}{82}=0.3049\ h[/tex]
She takes t2=36 minutes to drive the remaining distance. 36 minutes is 36/60=0.6 h, thus the total time is:
[tex]t_t=0.3049\ h+0.6\ h=0.9049\ h[/tex]
The average speed is:
[tex]\displaystyle \bar v=\frac{45}{0.9049}=49.73\ km/h[/tex]
Anna drove at an average speed of 49.73 km/h
