Answer:
the magnitude of gravitational force is 6 x 10⁻⁸ N.
Explanation:
Given;
mass of the two people, m₁ and m₂ = 90 kg
distance between them, r = 3.0 m
The magnitude of gravitational force exerted by one person on another is calculated as;

where;
G is gravitational constant = 6.67 x 10⁻¹¹ Nm²/kg²

Therefore, the magnitude of gravitational force is 6 x 10⁻⁸ N.
The answer is D.) all of the above
Answer:
25 m/s in the opposite direction with the ship recoil velocity.
Explanation:
Assume the ship recoil velocity and velocity of the cannon ball aligns. By the law of momentum conservation, the momentum is conserved before and after the shooting. Before the shooting, the total momentum is 0 due to system is at rest. Therefore, the total momentum after the shooting must also be 0:

where
are masses of the ship and ball respectively.
are the velocities of the ship and ball respectively, after the shooting.



So the cannon ball has a velocity of 25 m/s in the opposite direction with the ship recoil velocity.
Answer:A air
Explanation:Of the three mediums (gas, liquid, and solid) sound waves travel the slowest through gases, faster through liquids, and fastest through solids. Temperature also affects the speed of sound.
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