A boy takes 20 minutes to cover 3.2 km on a bicycle find the speed in km/hr​

Two red blood cells each have a mass of 9.0 multiply.gif 10-14 kg and carry a negative charge spread uniformly over their surfaces. the repulsion arising from the excess charge prevents the cells from clumping together. one cell carries −2.50 pc of charge and the other −3.10 pc, and each cell can be modeled as a sphere 7.5 μm in diameter. (a) what speed would they need when very far away from each other to get close enough to just touch? assume that there is no viscous drag from any of the surrounding liquid. answer is: 321 m/s how do i find this (b) what is the maximum acceleration of the cells in part (a)? answer is: 1.38e+10 m/s2 how did they find this answer

Determine the maximum r-value of the polar equation r =3+3 cos 0

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.