Question

A jogger runs north 6 km, 5 km east, and 4 km north again. Time is 1.9 hr. What is average velocity?

Answer 1

Average velocity = 5.9 km/ hr (or 1.64 m/s).

Step-by-step explanation:

Velocity =
`(displacement)/(time)`

It is a vector quantity and has an SI unit of m/s.

Displacement =
`\sqrt{x^(2) + y^(2) }`

x = 5 km east

y = 6 km north + 4 km north

= 10 km north

So that,

Displacement =
`\sqrt{5^(2) + 10^(2) }`

=
`√(25 + 100)`

=
`√(125)`

= 11.1803

Displacement = 11.18 km = 11180 m

Time = 1.9 hr = 6840 seconds

Average velocity =
`(11.180)/(1.9)`

= 5.8842

Average velocity = 5.9 km/ hr

The average velocity is 5.9 km/ hr (or 1.64 m/s).