Gravitational Force and Power:
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The gravitational force acting on an object is given by the formula F = mg, where m is the mass of the object and g is the acceleration due to gravity (approximately 9.8 m/s² on Earth). The power due to the gravitational force can be calculated using the formula P = Fv, where P is the power, F is the force, and v is the velocity of the object.

Highest Point of Projectile Motion:
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When a projectile is launched at an angle above the horizontal, it follows a curved path called a parabola. The projectile reaches its highest point when its vertical velocity component becomes zero. At this point, the object momentarily stops moving vertically and starts to fall back down due to the force of gravity.

Calculating the Highest Point:
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To calculate the highest point of the projectile's motion, we can use the kinematic equation for vertical motion: v² = u² + 2as, where v is the final velocity, u is the initial velocity, a is the acceleration, and s is the displacement.

Given:
- Mass of the object (m) = 2 kg
- Initial velocity (u) = 20 m/s
- Launch angle (θ) = 60°

First, we need to find the vertical component of the initial velocity (u_y). This can be calculated using the equation u_y = u * sin(θ).

u_y = 20 m/s * sin(60°) = 20 m/s * √3/2 = 10√3 m/s

At the highest point, the vertical velocity component (v_y) becomes zero. Using this information, we can calculate the displacement (s) using the equation v_y² = u_y² + 2as.

0 = (10√3 m/s)² + 2 * (-9.8 m/s²) * s

Simplifying the equation:

0 = 300 m²/s² - 19.6 m/s² * s

19.6 m/s² * s = 300 m²/s²

s = 300 m²/s² / 19.6 m/s²

s = 15.31 m

Calculating the Power:
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Now that we know the displacement at the highest point, we can calculate the force (F) using F = mg. Since the object is at its highest point, the force is equal to its weight.

F = 2 kg * 9.8 m/s² = 19.6 N

Finally, we can calculate the power (P) using P = F * v.

P = 19.6 N * 20 m/s = 392 W

Therefore, the power due to the gravitational force at the highest point of the projectile's motion is 392 W.

Answer: A) 392 W