1. A plane is flying from Indianapolis to Los Angeles with an air speed of 211 km/hr towards the west. The air current that day is blowing at 12 km/h towards the east. Find the speed of the plane relative to the ground.

2. A tug boat called SS Walnut is traveling upstream with a still water speed of 22 km/h in a river with a current of 5.0 km/h. What is the velocity of the boat relative to an object on the shore?

3. Dante flies his jet plane from Spokane, WA to Cincinnati OH. The plane flies towards the east with a ground speed of 740 km/h. The wind that day is blowing from the west with a speed of 38 km/h. What is the jet's air speed?

4. A kayaker traveling downstream is pulled out of his kayak in a river with a current of 31 km/h. The Kayaker continues downstream. A hiker on the shore observes the kayaker to be swimming at 33 km/h. What is the kayaker's still water velocity?

5. A prop engine plane takes off from the ground and reaches its cruising altitude and air speed of 216 km/h towards the east. At this altitude the easterly wind speed is measured at 67 m/s.

a. What is the plane's ground speed while flying at this altitude?

b. What is the distance this plane has flown after 7.0 hours at its cruising altitude?


Sagot :

Answer:

1.199km/h towards west

2.17km/h towards upstream direction

3.702km/h towards east

4.2km/h towards downstream direction

5.a.149km/h towards east

   b.1043km

Explanation:

1.V p,e = Vp,w + Vw,e

           = 211km/h-12km/h

           =199km/h towards west

2. Vb,o=Vb,r+Vr,o

    Vb,o=22-5km/h

          =17km/h towards upstream direction

3.Vj,w= Vj,e + Ve,w

   Vj,w = 740-38km/h

          = 702km/h towards east

4.Vk,r= Vk,e+ Ve,r

   Vk,r=33 - 31km/h

        =2km/h towards downstream direction

5.a.Vp,e=Vp,w +Vw,e

      Vp,e=216-67km/h

          =149km/h towards east

b. distance =speed * time

                 = 149km/h * 7h

                 =1043km

[V p,e-velocity of plane relative to earth(ground)]

[p-plane ,w-wind ,e-earth, b-boat, r-river, o-object, j-jet, k-kayaker,]