Van der Waals forces are relatively weak interactions that exist between electrically molecules because of the molecules' uneven distribution of charge.

Van der Waals forces are relatively weak interactions that exist between electrically uncharged molecules because of the molecules' uneven distribution of charge.

Explanation:

Vanderwal forces are known as weak intermolecular (molecules of different substance) force existing between elements of different charges. It mainly exists in uncharged or neutral molecules. This molecules possesses poles (one positive while the other negative). This interaction between the poles (dipole) of the elements makes the molecules neutral. This interactions occur in solid and liquid gases. The solid molecules are also known to have lower melting point and the interactions with other compounds are weak.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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