The question seemed easy at first but my answer is different to the answer in the back of the book.
Sally travels from St. Kilda to Camberwell (12km) in 2hrs. She then returns to St. Kilda - taking another 4hrs.
Calculate her average speed in km/h and m/s.
Inititally I just divided the total distance (24km) by the total time (6hr) and got around 4km/hr and 1.11m/s. But according to the answers at the back of the book the answers are 4.5km/hr and 1.25m/s.
How do I get that result?
Sally travels from St. Kilda to Camberwell (12km) in 2hrs. She then returns to St. Kilda - taking another 4hrs.
Calculate her average speed in km/h and m/s.
Inititally I just divided the total distance (24km) by the total time (6hr) and got around 4km/hr and 1.11m/s. But according to the answers at the back of the book the answers are 4.5km/hr and 1.25m/s.
How do I get that result?
-
s=vt
12=v*2
v=6km/h
s=v1*t1
12=v1*4
v1=3km/h
average speed=(v+v1)/2=9/2=4.5km/h or 4.5*1000/60*60=1.25m/s
12=v*2
v=6km/h
s=v1*t1
12=v1*4
v1=3km/h
average speed=(v+v1)/2=9/2=4.5km/h or 4.5*1000/60*60=1.25m/s