1. When substances form mixtures, the substances

a. keep their original properties because no chemical changes occur.

b. react to form a new substance with new properties.

c. combine in a specific mass ratio.

d. always change their chemical state.

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You want to move a heavy box with mass 30.0 kg across a carpeted floor. you pull hard on one of the edges of the box at an angle 30∘ above the horizontal with a force of magnitude 240 n, causing the box to move horizontally. the force of friction between the moving box and the floor has magnitude 41.5 n . what is the box's acceleration just after it begins to move

In the equation for the gravitational force between two objects, which quantity must be squared? m1 m2 g d