1. is D. Scientific method cannot be replaced.
2. is B.
3. is B as well.
A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. (According to ck12.org)
So your answer would be A!
Answer:
Explanation:
Gravitational law states that, the force of attraction or repulsion between two masses is directly proportional to the product of the two masses and inversely proportional to the square of their distance apart.
So,
Let the masses be M1 and M2,
F ∝ M1 × M2
Let the distance apart be R
F ∝ 1 / R²
Combining the two equation
F ∝ M1•M2 / R²
G is the constant of proportional and it is called gravitational constant
F = G•M1•M2 / R²
So, to increase the gravitational force, the masses to the object must be increased and the distance apart must be reduced.
So, option c is correct
C. Both objects have large masses and are close together.