An airplane took 2.5 hours to fly 625 miles with the wind. It took 4 hours and 10 minutes to make the return trip against the same wind. Find the wind speed of the plane in still air

The wind speed of the plane in still air is 50m/h

Explanation:

Let p = plane speed in the air

Let w = wind speed.

since , we can;

(Eqn1) can be simplified further into

In (Eqn2), multiply both sides with the reciprocal of which gives us

So we have;

p - w = 150

p + w = 250

2p = 400

p = 200

Put p (200) into p - w = 150;

200 - w = 150

w = 50

Therefore,

The speed of the plane in still air is 200m/h,

The wind speed is 50m/h.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards