Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.
When the temperature increases, the kinetic energy of the particles increase this inturn makes them vibrate
At 3.5s the distance would be 10.85
Find 1/4th of 2.00 and add that to 6.2