Answer:
0.72 kg per cubic m
Explanation:
Mass = 14.4 kg
Volume = lbh = 4*1*5 = 20 cubic m

Gravitational force equals GMm/r^2, where G is constant, M and m are the masses, and r is distance.
For I, if both masses double, the formula becomes G2M2m/r^2, or 4GMm/r^2. Therefore, the gravitational force will quadruple or 4x.
For II, if the distance between the object doubles, the formula becomes GMm/(2r)^2 or GMm/4r^2. In this case, the gravitational force is 1/4x the initial force.
Answer:b
Explanation: i took the test and b was correct
Friction can be reduced by making the surface smoother, lubricating the surface, or reducing the contact between the forces.
Hope this helps!