Respuesta :
Answer:
Speed = 4.67 km/h
Velocity = 3.33 km/h
Explanation:
Part a)
As Mary walk Towards North for 4 KM
and then she turns right and walk another 3 KM
so the net displacement of the Mary from her house is given as
[tex]displacement = \sqrt{4^2 + 3^2} = 5 km[/tex]
while the total distance moved by her
[tex]distance = 4 + 3 = 7 km[/tex]
now average speed is defined as
[tex]speed = \frac{distance}{time}[/tex]
[tex]speed = \frac{7 km}{1.5 hr}[/tex]
[tex]speed = 4.67 km/h[/tex]
Part b)
average velocity is the ratio of displacement and time
[tex]velocity = \frac{displacement}{time}[/tex]
[tex]velocity = \frac{5 km}{1.5 hr}[/tex]
[tex]velocity = 3.33 km/h[/tex]