I'm pretty sure the answer is d.The weight of the book and the table's upward force on the book are equal in magnitude but opposite in direction.
Answer:
Velocity of airplane is 500 km/h
Velocity of wind is 40 km/h
Explanation:
= Velocity of airplane in still air
= Velocity of wind
Time taken by plane to travel 1150 km against the wind is 2.5 hours

Time taken by plane to travel 450 km against the wind is 50 minutes = 50/60 hours

Subtracting the two equations we get

Applying the value of velocity of wind to the first equation

∴ Velocity of airplane in still air is 500 km/h and Velocity of wind is 40 km/h
The answer is B I hope this helps luv