The wind is blowing from west to east at 35 mph and an eagle in that wind in flying at 22 mph relative to the air what is the velocity of this eagle realtive to a person standing on the ground if the eagle is flying (a) from west to east relative to the air and (b) from east to west relative to the air?
Can some one show me how to start this ?
It's the same situation as a boat in a river. If the river flows at 2 mph, and the boat moves at 3 mph in the direction of the flow of water, then the boat is moving 3 mph faster than the water. For an observer on the shore, the boat moves at 3+2 = 5 mph. downstream.
Inversely, if the boat moves against the water, the observer will see that the boat moves at 3-2=1 mph upstream.
Can you give it a try now?
So it would be 35 +22 = 57
and 35-22 = 13 ???
Good, the answers are correct!
(if they refer to questions (a) and (b) respectively)
that seemed to easy for physics ???
Physics is not difficult at all as long as you make sure you understand how it works, which is what you have done.
Continue the good work!
To solve this problem, we need to understand the concept of relative velocity. The velocity of an object relative to another object is the difference between their individual velocities. In this case, we have three velocities: the wind velocity, the eagle's velocity relative to the air, and the eagle's velocity relative to a person on the ground.
To start, let's consider the situation when the eagle is flying from west to east relative to the air. In this case, the eagle's velocity relative to the air is 22 mph, and the wind is blowing from west to east at 35 mph.
To find the eagle's velocity relative to a person on the ground, we need to consider the vector addition of the eagle's velocity and the wind velocity. When two velocities are in the same direction, we add them, and when they are in opposite directions, we subtract them.
(a) From West to East:
The wind is blowing from west to east at 35 mph, and the eagle is flying from west to east relative to the air at 22 mph. To determine the eagle's velocity relative to a person standing on the ground, we add the eagle's velocity to the wind velocity.
Velocity of the eagle relative to a person standing on the ground = Velocity of the eagle relative to the air + Velocity of the wind
= 22 mph + 35 mph
= 57 mph (from west to east)
(b) From East to West:
Now, let's consider the situation when the eagle is flying from east to west relative to the air. Since the wind is blowing from west to east, the relative velocity of the eagle and the wind will be different.
Velocity of the eagle relative to a person standing on the ground = Velocity of the eagle relative to the air - Velocity of the wind
= 22 mph - 35 mph
= -13 mph (from east to west)
Therefore, the eagle's velocity relative to a person standing on the ground is 57 mph from west to east when the eagle is flying from west to east relative to the air, and -13 mph from east to west when the eagle is flying from east to west relative to the air.