When the rocket is halfway between the earth and the moon, the force of gravity

Stronger than the force of gravity due to the moon.

Explanation: The force of gravity due to earth is stronger than the force of gravity due to the moon. Since the rocket is halfway between the earth and the moon, the force of gravity due to earth is stronger but not as strong as it is if it is closer to the earth's center. It will be upto 10 times stronger than the force of gravitydue to the moon.

We will use the trigonometric ratios to know the helicopter's deceleration speed. Later applying the concept of speed as a vector component of the value found we will find the vertical speed.

The 2% grade indicates that for every 100 meters traveled in the x direction, there is an ascent / descent of 2 meters. Therefore we will have the relationship

Now you would have the value of the angle tangent would be

From this relationship we could conclude that the vertical speed would be

Therefore the component of the helicopter's velocity perpendicular to the sloping surface of the hill is 6.78m/s