What potential difference is needed to accelerate a He+ ion (charge +e, mass 4 u) from rest to a speed of 3.5 x 106 m/s? (mass of a proton = 1.67 x 10-27 kg, charge of electron = 1.6 x 10-19 C)

In proton-beam therapy, a high-energy beam of protons is fired at a tumor.  As  the protons stop in the tumor, their kinetic energy breaks apart the tumor’s DNA, thus killing the tumor cells. For one patient, it is desired to deposit 0.08 J of proton energy in the tumor. To create the proton beam, protons are accelerated from rest through a 8.0×103 kV potential difference. What is the total charge of the protons that must be fired at the tumor? 

A 5.0 

Two 4.3 cm x 4.3 cm metal plates are separated by a 0.22 mm thick piece of Teflon. (Dielectric constant for Teflon (

Household wiring often uses 2.0 mm diameter copper wires. The wires can get rather long as they snake through the walls from the fuse box to the farthest corners of your house. What is the potential difference across a 19 m long, 2.0 mm diameter copper wire carrying an 9.0 A current?  (Resistivity of copper = 1.7 x 10-8 

Use properties of logarithms to expand each logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator.  

Write the equation in its equivalent exponential form: 

State the domain of the function.        

What is the role of the pigment molecules (such as chlorophyll) in photosynthesis?

What is the overall purpose of mitosis? (Hint: the answer is NOT to split a cell in two)