Part $1$:

Use a search engine to determine the speed of the fastest man$-$made object. What is the length of this object in its rest frame and the contracted length as seen by a stationary observer?

Hint: The binomial approximation for very small x is:

$(1+x{)}^a$~~$1+ax$

What does the fact that this approximation works at all imply about the difference between the speed of light and the speed experienced in our everyday lives?

Part $2$:

A metal surface is illuminated by light with a wavelength of $450$ nm $.$ The maximum kinetic energy of the emitted electrons is found to be $1\mathrm{.}50$ eV $.$ What is the maximum electron kinetic energy if the same metal is illuminated by light with a wavelength of $350$ nm $?$