Best Answer:<span> </span><span>The net angle between the direction of flight of the aircraft and the wind in the opposing direction is 20. THe component opposing the aircraft is 2.4*cos 20 KN
= 2400 * 0.9397 = 2255.2622 N. The distance covered is 120 Km
The work done by the aircraft overcoming the wind is
= 2255.2622 * 120000 = 270631464 = 2.71 x 10^8 N
As the question is trickily worded as : the work done on the plane by the air (wind) the answer is -2.71 x 10^8 J . (fourth option)</span>
Answer: D
Explanation:
When an object falls gravity is pulling down on it and is picking up speed, but as it gains speed air resistance becomes a faster. Air resistance increases with speed. And that force keeps it from accelerating eventually the object will pick up speed such that the force due to air resistance will keep it from getting any more speed at that point force due to air resistance is equal to its weight (mg) and the net force is equal to zero so it won’t accelerate any more at that point it is said to be moving in terminal velocity.
When an object has reached terminal velocity, it will have a constant velocity
Answer:
The ice melts mass is:

Explanation:
Kinetic Energy



Heat gained by ice= mass(g) x 80 cal
( 1 cal = 4.184 *10^7er or g cm^2/ sec^2)
Assuming no loss in heat, in the motion so both continue with temperature 0~C
To find so the mass (gm) of ice melted


V = u + at where u is initial velocity (15 m/s), a is acceleration (2m/s^2) and t is time (15 seconds)
V = 15 + 2 X 15
V = 45 m/s
All the boats operating at night requires Navigation light.
Navigation light helps prevent collisions between boats and see if visibility is poor. The types of boat are : Rowboats, Tug boats, Vessels, Sailboat etc.
Various boats have different lightning color to show its use and side of the boat.