An airplane has a velocity of 907 km/hr westward relative to the air. if the air is moving eastward at 82 km/hr, what is the velocity of the airplane relative to the ground? a. 989 km/hr eastward b. 825 km/hr eastward c. 989 km/hr westward d. 825 km/hr westward

D.  825 km/hr westward

Explanation:

In order to solve the problem, we should define a positive and a negative direction for the velocities.

Let's take positive (+) as westward and negative (-) as eastward.

1) Relative to the ground, the air is moving eastward at 82 km/h, so the air velocity is

2) Relative to the air, the airplane is moving westward at 907 km/h, so its velocity is

In the reference system of the ground, the velocity of the airplane will be given by the velocity of the airplane in the reference system of the air (v) plus the velocity of the reference system of the air relative to the ground (v'):

Therefore, substituting:

And the sign (+) means its direction is westward.

trig 15.3 cos

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min