contestada

An unladen swallow that weighs 0.03 kg flies straight northeast a distance of 125 km in 4.0 hours. With the x x direction due east and the y y direction due north, what is the average momentum of the bird (in unit vector notation)?

Respuesta :

Answer:

The average momentum of the bird is 0.26 kgm/s

Explanation:

The formula to be used here is that of momentum which is

momentum (in kgm/s) = mass (in kg) × velocity (in m/s)

The velocity of the bird is

velocity (in m/s) = distance (in meter) ÷ time (in seconds)

distance in meters = 125km × 1000 = 125,000 m

time in seconds = 4 hrs × 60 × 60 = 14,400 secs

velocity = 125000/14400

velocity = 8.68 m/s

momentum (p) = 0.03 × 8.68

p = 0.26 kgm/s

The average momentum of the bird is 0.26 kgm/s

The average momentum of the bird (in unit vector notation) is (0.1842i + 0.1842j) kgm/s.

Total displacement

Since the unladen swallow that weighs 0.03 kg flies straight northeast (that is at a bearing of 45°) a distance of 125 km in 4.0 hours.

Its position vector after 4.0 hours is d = (125kmcos45)i + (125kmsin45)j = (125000 × 1/√2)i + (125000 × 1/√2)j

= (62500√2)i + (62500√2)j.

If the initial position of the swallow is d' = 0i + 0j, then its total displacement after 4 hours is, D = d - d'

= (62500√2)i + (625000√2)j - (0i + 0j)

= (62500√2)i + (62500√2)j m

Average velocity

The unladen swallow's average velocity, v = D/t where

  • D = total displacement = (62500√2)i + (62500√2)j m and
  • t = time = 4.0 hours = 4 × 60 min/hr × 60 s/min = 14400 s

So, v =  [(62500√2)i + (62500√2)j m]/14400 s =  (88388.35)i/14400 + (88388.35)j /1440

= 6.14i + 6.14j m/s

Average momentum

The average momentum of the unladen swallow is p = mv where

  • m = mass of unladen swallow = 0.03 kg and
  • v = average velocity = 6.14i + 6.14j m/s

So, p = mv

p = 0.03 kg × (6.14i + 6.14j m/s)

p = (0.1842i + 0.1842j) kgm/s

So, the average momentum of the bird (in unit vector notation) is (0.1842i + 0.1842j) kgm/s.

Learn more about average momentum here:

https://brainly.com/question/25941500